I can think of a reason!
Because I the ONLY device the damn publisher decided was a threat to its copyright was the Windows Phone, and I would really like to opt for the $150 dollar savings and rent the textbook I need (using kindle on my phone as the reader as it's the only portable device I have). I realize this is just a isolated issue affecting only myself as far as I know. But it is a legitimate reason, in my opinion, especially as I would have absolutely no need for the book after the semester ended and would delete it afterwards.
I have no problems paying reasonable prices for material, but the only option I have now is to pay a $150 premium for a hard copy because I use a Windows phone instead of an Android or anything else? Just a major bummer.
Anyway, just thought I'd add my 2 cents to the discussion, I guess I will take off my tin foil hat and accept defeat.
Heck I'd be happy to keep the time restriction if I could just port the thing to kindle on my phone somehow....