Each persons tolerance to a perceived erosion in the value of dollars spent at Disney is different, hence the reason you'll never get an unanimous opinion. We were DVC members and enjoyed the heck out of all our trips, and I'll never regret spending the money we did. Lots of great memories and we got out when we felt there was better value in other vacations.
That said, my perception of the value I was spending on a Disney vacation was eroded by the implementation of FP+. Sorry, I just didn't like the system and to this day I still don't. That was my tipping point, but there were other things Disney did that bugged me like the reduction in summer hours as well as the reduction in EMH. Those two negatively effected my perceived value of the dollars I was giving Disney.