Grip stability/technique issues ("limp-wristing") isn't an unknown problem among firearms instructors and armorers.
I have a fair number of different armorer manuals out at my bench, from different manufacturers, and "grip" issues are a commonly listed probable cause of extraction/ejection & feeding stoppages.
Not supporting the frame (and thence the gun's functioning during unlocking/cycling/locking) can create problems.
So, too, however, can low (or over) powered ammunition, as well as defective, worn-out, damaged or over-powered recoil springs.
Then there's dry guns ... and even worse, dirty & dry guns.
Don't forget excessively lubricated guns, though, with their accumulating sludge, grit, fouling, etc.
Now, the fun really starts when you start to combine varying degrees of all these issues in any particular combination of gun, shooter & ammo.
"limp-wristing"? Sure, it can happen, but ...
While some folks can't seem to grip the gun properly enough to prevent it from happening, there's other folks who can't get it to happen no matter hard they try to make it happen.
Depends.
I've watched ordinary qual sessions, along with T&E of different pistols, where a particular pistol & case of ammo runs fine in the hands of one shooter, but exhibited obvious grip related stoppages in the hands of another shooter ... but
that shooter only had that sort of grip stability issue occur with one make/model/caliber, not others.