Does it though? I'm not disagreeing with you, just asking for the sake of discussion.
The way I understand it, Universal gets its Marvel merchandise from a warehouse that sells the stuff to all kinds of outlets from Universal to CVS. But the only money Universal keeps are the margins of what they mark the stuff up at (since they're dipping into their own wallets to buy it from a vendor). So while Universal gets the benefit of selling a lot of merchandise, they're feeding Disney's bottom line in doing so (someone correct me if I'm wrong).
Meanwhile, a different property with closer ties to Universal might be a different story. If they were to negotiate for the rights of a new property, Universal has the opportunity to develop their own merchandise and keep 100% of that money away from Disney's pockets. Granted, it costs more money to get a new IP than to use one they already own, but theme parks know that merchandise is the key to a successful expansion. It's possible that despite the humongous amounts of people a new Marvel attraction would bring in, another property has the potential to be more lucrative just because merchandise is a more sought-after revenue stream than ticket sales.
Me personally, I want a Marvel ride and if Disney can't make one then I want Universal to. I think that it's the easiest of the latest big blockbuster franchise to turn into a great theme park ride. It has way more potential than most of the stuff people talk about on here. If Universal went balls to the wall in creating some new technology to give us an Avengers ride I might never go to any theme park ever again. But I would think they care less about that and more about their bottom line.
