I'm not the biggest expert, but thankfully you don't need to be to figure out all the obvious stuff
1) both boxers are kind of awful outside the ring, though mayweather is about ten times worse
2) boxing matches aren't actually made by an outside committee or booker like MMA, someone just tosses out who someone should face and then the two boxers talk how much money it'll be
3) with that in mind, there's also no centralized system for a championship like the UFC, it's just a bunch of "committees" that all have their own titles. this is a problem because there's not really any truly major one, just a whole buncha little ones, so all of their titles mean nothing
4) this was a matchup that should have happened in like 2011 when the two boxers actually mattered more, except mayweather was a prick so it didn't happen
5) it costed A HUNDRED GOD DAMN DOLLARS to watch this single snorefest of a match, and the people setting up the PPV legit believe it'd do buyrates in the 3 million