Never heard someone downplay something so blindly. The sight can experience huge temperature swings in all weather conditions. Pulling the gun out of a warm car into -30 temperatures?? Then squeezing off a few mags and warming the receiver up by 100 degrees? Or perhaps pulling the gun out of a boiling hot car trunk on a hot humid summer day??
Sorry but your downplay is bogus. A 4" shift at 100 is hardly noticeable??? Jeez.
So how many times do you do those things? Did you notice that you couldn't hit the evil gong downrange? You weren't comfortable shooting around the hostage to hit the terrorist in the eye?
I'm not saying the claims are untrue but my EOTech XPS has never shifted more than an inch or so from one range session to the next or throughout the day as the rifle warms up. A click or two correction is all that's ever needed and I don't even notice it unless I put the rifle on the sandbags to verify my zero.
You realize that your ammo does the same thing right? Shoot at -20c and after a few shots the chamber is nice and toasty and if you let a round sit in there and warm up you will have a POI shift. Same thing if you sight in when it's cold out then shoot the same ammo when it's 25c and you've just pulled the ammo from your hot trunk.
Maybe we should all just start slamming every ammo manufacturer for their substandard ammo. Even "temp stable" powders do it to a certain degree.
This is why as a civilian shooter this doesn't bother me, there are so many factors that effect your POI that a small shift of your sight zero on a range day is of very little concern to me. No one is shooting back, I'm not being scored on my first 5 shots, which is all it would take to test and adjust the sight. If I'm shooting offhand I'm pretty sure I'm wobbling at least 4 moa.
So yes, a 4 inch shift at 100 is hardly noticeable unless you're a bench shooter, at which point I would tell you that you're probably using the wrong optic for your application.
Don't be lazy, bang... click, click.... bang.... click... bang... there it's back on zero for now. It isn't that hard to adjust and even if you're law enforcement or military I really doubt anyone is going to be using their dot sight equipped rifle for precision work at 100m, they're going to wait for the squad marksman and his bolt action to show up to shoot the terrorist who's hiding behind the civilian.
And 4moa is still a center of mass hit at 100m so is it really that noticeable? Especially if you throw some adrenaline into the formula and now you're bouncing all over the place.
Typical internet hype, exaggerate everything and make a mountain out of a molehill.