Please. They aren't making anyone do anything. If people want to experience both parts of Potter, then they buy two-park tickets. If they don't, they don't have to.
Your analogy is off because Hogwart's Express is going to be maintained unlike the monorail ... oh, and it is an attraction, not simply transportation. In other words, your point is weak and not valid.
UNI is absolutely a better value when it comes to what they are offering for the price of admission (whether the ticket is one day one park, multi-day, or AP) than Disney.