Yeah
The 10mm Witness is probably my favorite autoloading pistol, but I won't buy them new simply because of EAA. I'll pick up used ones if they're cheap.
That being said, there are people with 10mm Witnesses with more than a few thousand rounds of full tilt 10mm loads. I think many of the slide cracks that have shown up are due more to manufacturing screw ups by Tanfoglio more so than the 10mm pressures and ability to generate slide velocity. They're is such a thing as too hard, and casting is a quite tricky process.
When I say drastically reduced life span, I mean
CZ 75B or Witness 9mm 50k+ rounds is not unusual
10mm Witness with full tilt 10mm loads, I'd expect 10k or less
Most Witnesses will last long enough for you to get your monies worth out of them.
EDIT: BTW, I believe the infamous Paul Richter is VP of EAA and possibly part owner. That should give you a good indication of why EAA will never change.