Whatever happened to common sense?
It seems people these days have nothing better than to find a reason, any reason. to be offended...
This is simply the demographic who is interested in seeing him perform.
It makes sense that he attracts middle-aged people who remember him from their youth and are after some nostalgia, ie a very limited audience.
What will you be offended by next?
Will you get offended if you see a majority of teenage girls & women at a One Direction reunion concert and complain that there should be more teenage boys and middle-aged men there? RA is has never been a cool entertainer or a great song writer/singer. His music is bland, manufactured pop. Although of course he come across as a nice, charming guy.
Will you get offended if you see lots of gay men at a Kylie concert because you think there should be more straight people in the audience?
Will you get offended if you see a Norwegian death metal concert with a lot of young people with tattoos and long hair in the audience and complain that there should more pensioners wearing tuxedos and buzz cuts?
Will you get offended if you see a majority of black teens at a Grime concert because you think there should be more white middle aged opera lovers there?
Frankly I would say most black people will have better musical taste and won't want to fangirl over Rick Astley...