You are making an ad hominem argument against vim's 'stability' using the fact the dev list has seg faults at the top. As a matter of course, seg faults/crashes are the most irritating bug a program can encounter. When they occur and are repeatable, it's likely they would become a popular topic of discussion, regardless of the frequency in which they occur.
Vim's stability and the occurrence of certain seg faults in it may appear to be related, but it isn't proof one leads to the other just because it's on some list somewhere.
I consider the term 'stability' to be related to overall dependability. I depend on vim on a daily basis, as do others here. It's yet to let me down.