I respect the way you feel.
I agree that not everything is exactly as it was when I bought in 2000.
But reading your post, a lot of what you describe is Disney and the parks. Not DVC.
I agree with the bland refurbishments. But, some of it I'm happy with. A little more whimsy would be more to my taste. Dirty rooms. I've been pretty lucky. I haven't seen the amount of dirt described on here. Not saying it's not happening. There was that one sofa with the very dirty arm. I called and it was cleaned, but - I should not have had to call.
I maintain an annual pass most of the time, so don't worry about how much a ride costs me. If I was paying by the ride I'd probably never ride anything.
Since I'm older I'm really paying for a pass to wander around in the parks, sit in a cool show once in awhile, have a meal in whatever restaurant will seat me - rarely make ADR's or fast passes. So what I'm expecting from Disney is significantly different from your family needs. Neither is wrong and both of us can choose with our feet.
There are definitely things that bother me in the overall picture. When I travel alone, I can almost count on being assigned a handicapped room. I've learned to check out the room because some of the accommodations are fine. Some aren't. So, most times that's where I sleep but if the room is the kind I truly dislike, I get myself moved. No apologies for that as I get those rooms way more than the average guest - when I travel solo. With family, never happens. Solo trips are 2-3 times per year.
I really dislike that when people have a problem and complain, instead of addressing problems that may impact all, they throw some fast passes at it. I'm not referring to stuff where someone should get compensation such as not getting their room in an acceptable time. Rooms should be ready by four and every hour after that is time I figure I paid for. After all, I also have a set time to vacate.
My other big peeve is parking.
So, I also have a small share of issues but so far I'll keep my points. I'm curious which resort you are going to sell? I keep wanting more Hilton Head points and have to hold myself back. I think the more invested we become, the more aggrieved we are at problems.