Musical taste is personal, however this is a very ignorant statement to say that they "totally suck". If they are not up your alley that's one thing...but they do not "suck".
Oh God, give me a fucking break.
Please don't try and tell me you have never used that phrase to refer to something
for which you had personal distaste for something, even though you knew full
well they didn't actually literally suck.
Let me give you examples on how this slur is used:
"Yankees suck" - now, do you really think that when people say that, that they
really mean that the Yankees are inept? No, they mean they have personal
distaste for that team.
"homework sucks" - now, do you really think that when people say that, they
mean that homework is bad for them? No, they are expressing personal
distaste.
I have never heard a Grateful Dead song that in any way appeals to me, so
I reserve the right to say that they suck.
Am I saying that they have no musical talent? No, I am expressing personal distaste.
Can I be any clearer?