PA hotels are really good value compared to most theme park resorts in Europe. There are regular promotions, free fastrack in some and cheap park entry or park entry included as standard. I would use the phrase 'pile them high, sell them cheap' - in that, they make money by sheer volume rather than price per head. For example, its easily 40% cheaper for a 4 night break at Gold River and tickets than, say, Phantasialand. That said, Spain in general is much cheaper than France and Germany.
It seems to work for them and certainly helps with foreign tourists. The impact of falling British visitors in 2019 will be interesting.
The main issue at PA for me is the evening activities (which isn't an issue May-August when park is open very late, or peak weekends), which Hard Rock Hotel would help massively, and the disconnect around the resort.