If I was going to be totally honest, a lot of the opinions that you express show a strong preference for mediocrity over good songwriting and musicianship.
Valid opinion, but wrong considering I like tons of stuff where the musicianship is above average. I really think your musicianship has to be above average to play anything in the genre so saying I like music that exhibits poor musicianship is nonsensical. It's like professional athletes: People say 'x person sucks' but they'll never have the talent to play at that level and don't understand what it takes to get there. Do they suck relative to 'y person'? That could be a debate and it's certainly manifested everywhere. Do you or I suck compared to a professional athlete? Yes.
I'm not really sure how you can say that the songwriting on SFV is inferior to the 70s stuff. If anything it's equal, but not necessarily better. SFV is probably the best 80s album from them IMO.