In my head I think it's because that genre of music was larger back in the day so blks cared less about non-blk outliers. People don't realize but blk R&B was a ridiculous musical force from 90s until around early 2000s. Think about the Grammy award winning groups topping overall charts Boyz2men, Whitney, Toni Braxton, TLC...
It's easy to be permissive of outside groups when the core is strong.
But our representation in the genre isn't like that anymore. So to have an outsider come and revive a time of musical genius and do it successfully is gonna have people feeling some type of way b/c it feels like blk sound is being reproduced without blk people.
And bless his little racially ambiguous heart, Bruno probably has the best of intentions. Probably grew up listening to Motown Philly like the rest of us. But it burns to see him getting excessive props knowing good and well that blk artists could hardly do it and pull the same crowd even though we culturally have more of a claim to that genre than he does.
Like I said, I can't be the only one who wishes it was a blk person singing every time he comes on the radio. It's kinda bittersweet.