I think it depends when you stay at Pop and what discounts you can get.
When I stayed at Pop in late August of 2015 (granted, that is one of the cheapest hotel "seasons" at WDW), I was able to get a discount that brought the room down to about $80-90 night .... cheaper than most "off the interstate" hotels like Hampton Inn, Comfort Suites, Holiday Inn, etc. I was very happy with that price. I've paid more for supposedly "better" hotels (like a Fairfield Inn or similar quality) in the Orlando area that are just worn down with no perks.
While the quality of the Pop rooms isn't better than your typical "Days Inn" .. it is much cleaner, better customer service, pools, and the perks of free Parking (or using Disney transportation). Just being in the "ambience" of Disney is worth the price to a lot of people as well (it was to me when I went). I'm there to spend times in the parks, so I just want a close and convenient bed to rest my head on. Not having to drive to the parks every day is a huge perk to me.
(Personally, I've found the way to go is to stay at house/condos .. cheaper, roomier, and a lot of them not that far away from the parks).