Research in general pretty much has to work this way. You're trying to identify "laws" or rules that govern reality. Outliers are interesting, but in general we expect to find many instances of some phenomenon—which means that by default we're looking for cause-and-effect relationships that apply in "most cases."

It's also worth mentioning that it's very easy for people to convince themselves that they're special or different when they actually aren't. Our own psychology is very unreliable. So while your point is well taken, people should also not assume they're the exception to the rule, even if they might be.