Instead you said a bunch of dumb shit.
And still:
"What happens if a boxer loses one of his first three fights? His career is probably over before it started. "
I've already showed you this statement is just WRONG.
Undercards are one of the biggest issues these days. It's partially because half of the great fighters now are Top Rank or Golden Boy and they won't make fights. While this only slightly affects the Main Events (as both promotions have large stables) the undercards are very very weak because of it. I can really only think of two boxing PPV's I "had" to buy (I won't buy a fight unless there are 3+ fights that are quality/interesting...this goes for UFC as well), the rest I just find a stream and deal with the low quality for the purpose of knowing what happened.
I've seen weak UFC undercards as well, FWIW...not to mention the dreaded injury bug derailing things. Shit cards happen, it sucks, move on.