I didn't say that everyone isn't entitled to an opinion. That's certainly true, but the validity of everyone's opinions isn't necessarily equal. For instance, I could have a certain opinion on rocketry (something which I know little about), but a certified rocket scientist who works at NASA will obviously have a much more valid opinion.
The whole notion that everyone's opinion is equal in cogency (not that everyone is entitled to an opinion) is an unfortunate byproduct of our increasingly egalitarian society. It's akin to giving trophies to everyone in a competition, even the losers.
Bottom line: everyone can have an opinion, but opinions are not always of equal value.
You're correct. Some things can't be put into opinions. You can't have an opinion on whether or not the the sun is shining. It's a fact. And it's a fact that Elvis has impacted music in extremely large ways. He was responsible for fusing blues and rockabilly and popularizing rock n' roll, elements of which incorporated themselves into other genres like metal, etc... And one assumption I have made is that everyone on this forum is into either rock, blues, metal, or any combination of them (considering that is is Jemsite). So unless you don't like any of those types of music (which could be true, in which case I stand corrected; chances are it's not though), then you certainly can't say he "sucks" with any valid argument to back it up. That's why I said it was such a sweeping, generalized statement. It's ridiculous in the sense that it overlooks everything he's done to impact the music we listen to today.
Sorry for straying off-topic. Carry on.