It's nothing to be ashamed of, it's always been a desirable trait, from my perspective, that was passed down from our ancestors hundreds of years ago and is ingrained in our roots that trace back to the motherland. I believe that certain desires one holds are what their ancestor's preferences and preferable traits in a partner were at the time and are often being passed down from them and influence the current generations of today.
To be a Black man and not like a woman with a big butt, something's gotta be wrong with him, and/or he's become too indoctrinated by the White man's/society's idea of beauty.
Hell, you could say the same thing about Black women preferring men who pack a big piece (pause). It's rare to find or hear a Black woman prefer a man with a little cactus; that's one of many reasons why Black men are Black women's preferred man of choice, in her eyes, the Black man's sexual prowess is unmatched.
African bruhs and women are the same way; sure, there are men of all races/ethnicities that might like a big butt as well but their perception of what a big ass looks like isn't the same. For example, a White man might find Scarlett Johansson to be a woman with a big ass for the ages, but to the average Black man, she'd likely be considered a no-ass/pancake ass-having woman; in other words, she ain't really got no ass.