I think they were fine in the beginning, I do like that you can often participate in competitions and win prizes but because they haven't really been developed and we don't have any way of customizing them they feel repetitive and overused now.
Maxis seems to add them to a lot of packs but I feel that they are not much more than a place to visit in order to do a few activities. They probably put in a lot of work in order to make them by making art and assets and creating tuning files and broadcasters but the end result feels a bit underwhelming when you have visited them a few times...
If they had been placed on an actual lot then maybe we could have customized them and added more things to them. In HSY they should probably have been located at the school and happen during school hours.