The straightforward answer is, "Because Razer is a big target and it's easy." Same reason people like to complain about Microsoft, Apple, and a lot of other companies, but that doesn't begin to answer all the underlying things.
Razer has had problems with its products, no denying that. A lot of people forget nearly every manufacturer has. Consider that people are usually much more vocal about negative experiences than they are about neutral ones. So if you see a lot of warnings on Newegg or Amazon about something being junk, take it with a grain of salt. People are much more likely to leave negative feedback about a product they didn't like than they are to leave positive feedback when something meets their expectations. Chances...