Yep, they're sticking to the dead middle of the road when it comes to music... On the one hand it's safe, marketable and is do inoffensive it will work for everyone from toddlers to gran and grandad. On the other hand, it's bland, insipid and mediocre pop rubbish that only children and families really listen to in the long run.
Unfortunately, as a family theme park inoffensive is where they have to stick to. A large rock concert may work to an extent, but expecting Glastonbury, Reading or Download is a step too far, at the end of the day it's a family resort.