It does that in the PS3 and PS4 apps as well. But it's easy to use directional buttons to make the credits full screen again. Regardless, it really takes you out of the moment at the end of a good movie where you just want to bask in whatever thoughts or feelings you might be having while enjoying the end credits soundtrack.
Almost worse for me, however, is when I'm browsing on the PS3 or PS4, and I select a movie or TV show just to read the description, it automatically starts running in the background. Even if I quickly exit out after a few seconds, it will show up in my watched lists. So not only is my watch list cluttered with a bunch of TV shows and movies I will never watch, but now I suspect I'm getting recommendations based on them. "Because of the five seconds you watched X movie, here are 20 other similar movies you may like ..."