I have no idea who the current "Mibba Famous" people are. I see names rattled off all the time, and usually have never seen that person around, or don't recall them. I dunno. "Back in my day," it was people like Lightning Zap...it's been so long, I can barely remember any of the others. Nowadays, people mostly just rattle off names of their own friends, regardless to if they're well-known on the site. (They might not even realize it's the case, though, to be fair. "I see this person around all of the time and notice them a lot, because they're my friend," etc.)
Being "Mibba Famous" is just a phase, I've come to realize. There will always be Mibbians that are somewhat well-known, but those who others slap the term of "famous" on tend to be fleeting. Like
ellis. said, it's just of the time period. People will barely start to complain about them before a new batch will roll in, usually.
EDIT: I just realized how bitchy this post sounds.
The whole "Mibba Famous" thing just puts me in a bad mood, sometimes. So many people complain about it, because they want to be but aren't, or they just irrationally hate anyone who gets named as such, and it's just drama and aaagghhh. It's such an inconsequential thing, but it can be a pet peeve of mine when discussed in certain ways.