I don't feel they are crap, but they are also not not crap.
I agree... They are a band that did well because of the teenage dollar.
They are like Pink Floyd... A british band with mostly American blues influence... This was the key to making money on the radio in the 70's... THE BLUES.
And yes... The riffs go on and on... Take Kashmir, for example... It's an interesting riff with some non-rock instrumentation. But it just goes on and on with the same motif.
I feel the same way about Pink Floyd. They don't suck. I have a few of their albums. But to say they are the best band ever, well, that's not saying much. Yes, Dark Side of the Moon is the best selling rock album ever. Does that mean it is great? All of the songs sound kind of the same -- the plodding tempo, boring drums, and blue-cheese guitar solos that aren't really interesting at all. The keyboard parts are boring. I am one of those with the opinion that progressive rock should have top notch musicianship and composition... Crud... even Marillion took some Pink Floyd ideas and expanded on them in a better way. But they did not play the blues, and were far too British to become successful here. Same think with early Genesis. To be successful in the 70's, British bands exploited American music -- mostly the blues.
These were accessible bands. They played the blues.
ba ba ba bow!