I see your point,
I think it all comes down to preference.
You're welcome to like what you want, just like others are welcome to like what they want.
Just that a good hip hop artist should have good lyrics, some versatility, a strong delivery, sound good on beat, possibly be able to freestyle, battle... whatever else...
Another factor is that a lot of these artists are trying to sound serious and be real and start talking all this thug shit while they aren't shit. In the end it still sells recorRAB or whatever, but personally.. I can't stand rappers like that. Music is a form of expression just as much as it is entertainment and bullshitting around...
You don't have to be a prophet on record but it's a plus if you can make commercial hits and still get respect from those that are more into lyrical content. Not to jock them but i think that's why Jay-Z, LL Cool J, Biggie lets say Nas have so much support because they can make a commercial record and have a lyrical record to show how versatile they are... which makes them great and loved by everyone..
I agree there is a lot of idiots that ride the underground bandwagon like there are no good mainstream rappers while a lot of underground rappers were actually inspired by those who have sold millions of recorRAB.
Underground rappers don't sell shit mostly because they don't have connections like that. A lot of them are independent, they can't get exposure without being on a major record label with connections.. Thus they stay open to a small audience, making little bullshit shows and recorRAB and advertising them by whatever means they can.. there are quite a few with more talent, better flow, delivery, lyrics and other things than many mainstream rappers but they need to work with the right producers and rappers to get their music out there.. otherwise they'll stay broke.
it's all a matter of prefence, it's just that hip hop is about versatility, freestyling, dj'ing, producing, lyrics, battles.. etc.. you don't neccessarily have to be able to do all that.. but this is part of the history aswell. Some mainstream artists have never been involved in any of that... they can't even sound good outside the studio.. they can't perform on stage or even write their own rhymes..
so what makes the person good in the end? if someone else writes for them, someone else produces for them and the music is sampled aswell so it's not original by any means... they can't freestyle, battle, flow right... nothing..
they are just an image.. not a real artist that can do something that others can't..