It doesn't matter if you are a fan of his or not, that kind of thing has no place in games like this.
That's not even mentioning the fact I only found out who he was because my girlfriend knows someone who likes Basketball and it got brought up. Common rule of the internet "you are never the only one" so there are going to be people wondering what the hell is going on and even more wondering why that's in a game like this.
While I agree wholeheartedly with you, I do think that they could get away with putting something in, without it being detracting.
e.g. during a basketball match (or training) at school, MC could pull a move and maybe credit Kobe with being the master of said move. That would give context, so anyone who doesn't know who he is should be able to discern that he is/was a basketball star plus, for those who do know who he is, it would be a little nod of the head.
As you say, entirely out of place in games of this nature, RL stuff and current affairs don't really need bringing into a fantasy life.
Could, however, be done contextually and cleanly, if the dev was a fan and wanted to pay tribute.