If you're upset about exclusivity in this deal I don't understand. These movies won't be on Hulu or Prime after this deal, but they aren't there currently. A whole bunch of movies are going to become more available for more people.
I don't personally care a whole lot but it's not difficult at all to understand why. The fact that they weren't on any services earlier left the possibility open for them to come to an arbitrary amount of services. Given how ubiquitous streaming services are becoming, one could reasonably consider this somewhat inevitable. The announcement of the exclusivity deal has collapsed the possibility space so now it's certain that they won't be coming to the other services (for the lifetime of the deal).