I think you'll find the indifference to the dining plan is due to something not a lot of us think about...
the prices are reflected.
The problem is.. you go on vacation with a Dining plan expecting to be compensated for it at least equally if not more so to make it worth your while. And in any case, you go and find that prices are reflected on every item you order. Thus people are adding it all up and figuring out whats worth it what isnt, etc. It hits on the ENJOYMENT factor immensely. Plus they have all the
free dining promotions to compare with.
If Disney took away the prices altogether and just said pay one price, eat as you like (but did as most all inclusives do) it wouldn't be a "thought" about it. People would go and just eat what made them happy. Not compare notes, etc. BUT then Disney would be compared with every all-inclusive and those who go to all-inclusives know what that would mean. (Who has the most restaurants to choose from? The most options?) Afterall people like OPTIONS.
Disney Dining Plan just adds to more of the work in planning. Some who like planning plan some who don't, cave. They don't want the added stress on vacation.
So yes it's a touchy subject especially where the DDP has changed in the last year - now people having to pay tips on top of it and taken away the appetizers which were once "there". The DDP has added new "options" and taken away on the "old options". Now if they'd added the new options and not taken away from the old, well probably people would have a different perspective. No one goes to an all inclusive and says "I dont go there anymore because of a, b, c - usually the food is either good or its not". Period.
While the DDP was a brilliant idea to begin with, it hasn't worked very well "in theory" because it's beginning to get a bad rap. It's a love/hate relationship between wanting and not wanting, taking/not taking it. Namely first because prices on everything is apparent and secondly because of the restrictions/changes.
Just my two cents worth not that it really matters.

I have my likes and dislikes about the DDP but I think differently about it than I once did for sure.
-T