Totally reasonable, there's a reason why Redbox/Netflix/iTunes/Amazon/Sony/etc. all offer rentals and I've used them all at one point. If you can't ever see yourself re-watching a movie or only doing so infrequently rentals can make a lot of sense.

I'm a bit of a digital packrat who likes to collect media, but a large chunk of my present movie collection is stuff for my daughter who wants to rewatch the same movie constantly so purchasing content to keep is the way I go 99% of the time.