It depends entirely on the bugs. If a bug's reproduction-path is rare enough that a non-critical mass of users runs into it, then it's not going to make a difference. Reddit, for example, is currently bogged down with login bugs, redirect bugs, redesign bugs, etc. and they're simply not prevalent enough to get people to mass exodus off of Reddit. Reddit will continue to grow fast even with these bugs.

The vast majority of user-seen bugs are not common. The common ones are usually caught with testing.