MMA isn't a team sport. Why are you comparing a team sport to prizefighting?
Anyway, team sports have a playoff bracket and sometimes teams with a .500 record or even a losing record can make the playoffs. So, teams coming off losses, even a string of them can still get the chance to win a title.
Team sports also don't have a reigning champion - a team wins one season and keeps that year's title. When they start the next season, they don't turn over a title when they lose. So, again it is another format.
You all are asking for a system that doesn't exist in prizefighting, has never existed in prizefighting. If you think the system is so bad now, how did you ever make it through the first 10 years of the UFC or Pride FC?
Pfft, bitching for a system that no one has even been able to come close to creating.
At what point did I saw anything about justifying a title fight based on popularity?
Those 3 that had a title fight coming off a lose were 1) a former title holder coming off a title challenge, 2) fighters coming off of another title fight.
What about that doesn't make them top fighters instead of just being popular?
A fighter can lose a title fight and still be ranked highly. Or in line for another title shot.
The PGA, players can get exemptions to the majors. They go down pretty low - top 60 or 70 on the money list for qualifiers. For some a champ from up to 5 or 10 years ago can enter the major (or another major) even if they are having a shitty year. PGA championship tournament - any former champ can enter. Top 15 from the year before can enter, even if that guy has been duffing all season long, he still has a shot at the PGA championship because of his finish the previous year. Why do you think they have so many qualifying markers? It is to get popular guys in that might be having a mediocre tour.
Let me guess, you also don't consider golf a sport.
edit: Since you think a team format is the best, did you watch the IFL?