I'd tend to be rather wary of such surveys - by their very nature, they tend to be "self-biasing" in that it's the people who DO have problems who rush to fill them in. I suspect - but I'm NOT going to claim it as a "fact"
- that the actual figure is enormously lower than that. Happy customers don't tend to come to sites like this and say "I'm not having any problems"; people come here to bitch and moan when they DO have problems.
I also suspect that the majority of broken screens come from "user abuse" (perhaps through ignorance) rather than being a design flaw in the machine.