I will agree with you on that, so many people refer to them as Soft Rock instead of Classic Rock.
I think there is also another aspect. Glenn mentioned it during the documentary and I've read it in many places, when they were leading up to why Bernie left the band, Glenn said that as they became more successful, Bernie had felt like they were selling out. I'm sure I remember this being a big issue in the To The Limit book as well as Felder's book, and not just with Bernie. I guess in SoCal back then, if you were successful, if you made money, you 'sold out'. I think a lot of people and probably media (not to mention friends and fellow musicians) thought the same thing.
I would never say that these guys don't appreciate the money they've made, of course they do, and they certainly aren't adverse to making more of it. I don't think money has ever really been their motivating factor, and certainly not now (or they'd be doing more shows). To me, they worked hard at their music and the sales, the money, was their verification that their hard work paid off. The success was validation of their efforts and decisions. The money was 'proof in the hand' that they'd given their fans what they wanted. Others saw that as 'selling out', the heck with the fans, music was to be all about what you (the musician) had in your head at the moment. As a fan, I can't respect that attitude.
Anyway, that 'selling out' attitude seemed to be pervasive back then and I think it's had a lot to do with a negative attitude being attached to them all along.