An undefeated record is a manifestation of immaculacy, a quality that is feminine in nature. This is why, at some point, a fighter's obsession with his own undefeated record demands a display of femininity in the form of avoidance, either by ducking competitors outright or avoiding them in their prime.
That is not to say that there is no place for femininity in boxing. There is a profound place for it, found hiding there in the latter half of that condensed and oft-repeated instruction on just how to perform the sweet science: "hit and don't get hit."
Not getting hit -- that's avoidance too, although we like to call it "being evasive." When it's accompanied by its masculine complement, i.e. striking, the two can blend into a whole that is greater than the sum of its parts. An awe-inspiring performance ensues that can almost too easily turn to fodder for poets.
Not surprising then that the boxer who single-handedly established an undefeated record to be the singular hallmark of greatness, Floyd Mayweather, was also a defensive genius. But just as quickly as it rose to brilliance, his defensive skill continued on to excess as he was unarguably too evasive, even going to the length of incorporating the clinch (a technically illegal move, mind you) as an integral part of his style. It's also not surprising that he beats up women. Macho displays of masculinity always belie an inner, unchecked, unconscious sensitivity (read: femininity). What's more, like so many males in our culture, Mayweather seems to have his energies reversed. The hackneyed joke said about him, in the form of advice, "a man is supposed to punch his opponent and hug his woman," is verily a truth said in jest. A gentleman should be manly to his enemies and gentle to his women.
At the least, fighters only taking on adversaries that they are sure to beat makes for boring fights. But it's much worse than that. There's so much risk, and so little reward. It's needlessly dangerous, as any macho display is. More than anything, ducking competition commensurate with one's own skill and courage makes for match-ups that fail to inspire. Observation is just a specialized form of communication and the essence of communication is commonality, or to put it more colorfully, resonance. I don't want to watch a boxer take on a challenge in which his victory is all but preordained, just as I wouldn't want to do that in my own life. It simply doesn't resonate with me.
Does it you?