First off, you're never going to get everyone to agree on this issue. If Disney prints a 'Do Not Tip These People' brochure for the resorts, then I'll follow those rules. I've always tipped housekeeping. No matter where I've stayed.
Second, I feel like housekeeping is more of a personal service. They are cleaning up after me. I'm not a messy person. However, when
I'm on vacation, I'm not making the bed or dumping the trash. It's worth a couple of bucks to have someone else do it. I mean, I paid over $1600 for a week, what's $2 a day as long as they do a good job.
Third, I used to be a housekeeper for a large hotel chain. It was a second job for extra money. I worked different floors during the week. That's why I tip every day. It's a lot of work if you do it right. A lot of work for minimum wage.
Last, reality check - There are people losing their jobs all over this country and living out of their cars.

You don't know what's around the corner. I try to remember that I am blessed to be able to go to WDW. Again, $2/day, no big deal.