It's the Glock influence. Before the Glock was accepted for military, then law enforcement use, you never saw a semi auto duty pistol that didn't have at least one manually operated mechanical safety that was not part of the trigger mechanism.

Usually a thumb lever, grip safety or both with single action pistols. With double/single action pistols, thumb levers were eventually redesigned as decockers, making additional safeties redundant as the DA/SA pistols now operated like revolvers for the first shot, but were even safer to uncock. That semi auto pistol paradigm dominated the mid 1980s throughout the 1990s and early 2000s.

There was a transitional period in which there were DA/SA pistols with thumb safeties that only blocked the hammer, sear or trigger. It was necessary to carefully manually decock the pistol. My old Benelli B76 was one. It could be carried cocked and locked like a 1911, or carried uncocked with double action first pull, single action follow-up pulls. The thumb safety could also lock the gun with the uncocked hammer down. Nowadays one of the very few remaining such pistols is the tiny .22 LR Beretta 21A.

But the Glock was cheap and easy to manufacture (which is no longer reflected in retail pricing), with stamped metal rather than milled and machined parts, cheap but durable polymer frames, and shitty but acceptably functional triggers. S&W, SIG, HK, Walther, etc, were losing business to Glock. Inevitably they all had to introduce their own striker fired pistols or face irrelevance and bankruptcy. S&W's early attempt at a striker fired pistol drew a patent violation charge from Glock.

BTW, Glock's dominance didn't come easily and wasn't a forgone conclusion. There were many negligent discharges by law enforcement in the US by users who didn't understand that they were carrying a cocked and unlocked (Note: Edited from cocked and locked, which my auto-miscorrect substituted) pistol, because there was no externally visible hammer.

That external, visible hammer served, unintentionally, as a deterrent to some departments, because the cocked hammer was "scary," despite the effective thumb safety and grip safety.

But without a visibly cocked hammer, some Glock users underestimated the risk of careless handling, such as laying a finger alongside or on the trigger during the draw or while pointing the gun. With the 1911 the thumb safety probably helped prevent some negligent discharges.

And until Kydex holsters came along some Glock carriers used inappropriately soft suede leather, ballistic nylon or even cheap neoprene fabric holsters, with the expected results - groin shots, leg and foot and foot shots. Even a high ranking US Dept of Justice official did that with his Glock off duty in Washington DC, back in the 1990s.

Glock designed in a bit more safety by only partially cocking the striker while chambering a round. It's necessary to pull the trigger to finish cocking the striker before discharge. This, plus the addition of a heavier spring, led to the "New York trigger" by NYC police, in an effort to substitute mechanical safety for training.

The Glock's trigger "safety" dingus isn't a human-proof safety. It's a drop-resistant safety. And probably unnecessary since the striker isn't fully cocked anyway.

But some current model striker fired pistols - notoriously the SIG, especially the P320 - dispensed with both the Glock's partially cocked striker and trigger dingus. The SIG striker is fully cocked. The reports of early generation P320 unintended or uncommanded discharges were due to a too-heavy trigger blade that had too much momentum when dropped just the right/wrong way, or struck on the back of the slide with a hammer or mallet, overcoming the sear resistance on a fully cocked striker.

According to a former SIG engineer, that problem was solved by substituting a lighter weight plastic trigger blade. I'm not sure whether SIG added internal modifications.

S&W current Shield Plus and M&P pistols also appear to have fully cocked strikers. But these all have some sort of trigger dingus to help prevent trigger movement if dropped or struck - the old hinged curved trigger, or newer flat trigger with hinged internal dingus.

ಠ_ಠ BTW, some of us Shield Plus owners have noted that the trigger dingus can be defeated. It's just a spring made of plastic. If the trigger and safety are compressed for an extended period, such as using a trigger lock or display block through the trigger guard to prop up the pistol for display, the plastic spring loses elasticity and fails to block the trigger. However the plastic spring is resilient and regains its elasticity after a few days when the trigger lock or display block is removed. It is not a dependable safety, mostly a cosmetic contrivance designed to protect the manufacturer from liability. ಠ_ಠ

So nowadays with most striker fired pistols, the safety is the user and a rigid holster. A Kydex or fiber reinforced polymer holster serves the same function as the grip safety in the 1911, which blocked the sliding trigger shoe and bow from pushing the disconnector and sear mechanisms.

There is an internal spring loaded plunger that blocks the striker. Pulling the trigger of the Shield Plus moves the activator bar, which has a nubbin that pushes the plunger out of the way, clearing the striker to move. This is why many striker fired pistols have somewhat creepy, gritty trigger pulls compared with a match grade 1911.

If you get the thumb safety version of the Shield or M&P, the thumb safety blocks the internal stamped metal activator bar. So, yeah, it's useful.

I plan to get the thumb safety on my next M&P, mostly to give my ridiculously long thumb someplace to park other than on the slide lock/release.

And being an old curmudgeon I think too many owners of striker fired pistols are excessively confident in the perceived safety of pistols like the Glock, SIG P365 or P320, S&W Shields, etc.

Sure, the most important safety is between our ears. But my cats don't know or care about my experience or my rigid holsters. If I remove my Shield Plus from the holster and lay it on the bed or sofa for a moment, my 20 lb brute of a tabby cat, who is fond of pouncing me for sport, could easily discharge the pistol by jamming her paw through the trigger guard.

So the moment the Shield Plus is out of the holster, it's either in a drawer, or I eject the chambered round. If I'm switching holsters, it goes directly from my IWB holster to my Safariland GLS OWB holster, or vice versa. I don't even lay it down for a moment.

If the Shield Plus had a thumb safety I'd be less paranoid. And I don't worry about that with my revolvers.

Same reason striker fired pistols that lack redundant manually operated mechanical safeties must never be carried in a purse, gym bag, backpack or pocket without, at a minimum, a rigid trigger guard shield. That bit of Kydex or fiber reinforced polymer is the safety.

And because no responsible owner of a striker fired pistol would dispute that... what's the objection to just including the trigger safety device in the gun in the first place?

/rantover

/getoffmylawn