Boxing is all about marketability.. if you take a lower payday than what you may be able to get, it most likely is with the intent to set up a bigger payday in the future..

Let's face it, in boxing if you're undefeated you're always marketable, but the more losses you have that marketability starts to fade, with the exception of some elite fighters.. With undefeated fighters there is always that excitement factor of, "will he be the first one to beat him?!" which gains interest from a lot of casual fans.

Although, i wouldn't say that they don't fight for glory. Boxers are as competetive as any other sportsman. But, i would say that money comes first, then glory.. but there is plenty of glory.