What do you expect from a sue-happy culture like we have today. Any set of drivers that has not been tested and appoved by Microsoft will raise that flag, in order to avoid lawsuits from people saying "The driver didn't work and I want $1 billion for pain and anguish!"
Seriously, most device drivers written over the past year or 2 will work on XP. I've got a ton of non-XP approved devices on my PC and it works just fine. But I won't say that a few Items took a little headscratching to figure out...
Hey, any of you remember DOS drivers? Manually figuring out DMAs, IRQs, etc.? Fun, wasn't it?
The only thing you should feel when shooting a terrorist: Recoil.