Ok, let me rephrase. A group which is majority black men playing basketball will, under many circumstances, engage in racial ("cracker", "wetback" or "nigger" - whatever fits) and non-racial ("yo momma") smack talk.
I strongly object to your characterization of black men. I've played pick-up and organized basketball with people of all races for > 15 years and this has not been my experience.
Honestly, it sounds like you don't play basketball, and certainly not with said "black men". I recommend trying it - I think it would change your mind.
I am speaking from personal experience, nothing more. I've played pickup on many occasions with lower middle class black men.
Also interesting to note: in my experience, in a mixed race group (e.g., in grad school), the smack talk will be toned down. The lone black guy will tone it down to fit in, just as I amp it up when I'm the lone white guy.
Lastly, please note: I'm not trying to portray trash talk as anything other than a harmless cultural practice which outsiders can be intolerant of.
(Note: not a hypothetical.)
Are they bad human beings for doing so?