10. The Undercard Was A Joke
In this day and age, fans ordering events on Pay Per View (read: those stuck in North America for the most part) are used to a certain amount of bang for their buck. Gone are the days where you could float a card with a headliner and leave a couple of cans nobody cares about on the undercard.
Promotions like the UFC and WWE tend to stack their cards whenever possible, and that's what fans want, because you never know when the headlining fight might turn out to be a dud.
Yet promoters lost sight of that with Mayweather-Pacquia, insisting that the main event was all that mattered. On paper, they were right, but since the fight itself turned out to be a dull affair (more on that later), the lack of a decent undercard became absolutely criminal.
How bad was it? There were only two other fights on the PPV card (a handful of other bouts went unaired):
WBC Super Bantamweight World Champion Leo "El Terremoto" Santa Cruz vs. Jose Cayetano and WBO Featherweight Champion Vasyl Lomachenko vs. Gamalier Rodriguez. While those are title fights, they're not really champions people care about - and Vasyl Lomachenko has only had five fights as a professional.
Apparently, that's what it takes to win a belt in boxing these days.