For me it is a tradeoff. The inconvenience of DRM against the convenience of ebooks in general.
Their are millions of paper books out there, but not as accessible for me as I work 6 months a year in a town without a book seller of any type. Even in the city no vender carries everything.
Of course all books are not available as ebooks, but between library loans, public domaine and multiple venders, I can always find something to read and not pay large sums to have them shipped. I may or may not strip DRM if I hate the formatting and it is not a library book but mostly I don't care.
As to not being able to read the book again and again, I have read a lot of books in my life, purchased, borrowed, acquired through the kindness of strangers etc. Approximately 200 a year for 50+ years. Most I have given away, donated, traded, lost in moving, had damaged by flood or fire etc. If I had them all today, where would I keep them?
When before, have we had the opportunity to keep so many books without a giant storage space. I am not altogether happy with DRM but I understand the publisher's view. If DRM currently makes more books available then I cannot entirely condemn it either and I am pretty sure it in itself is neither a virus of an infection. My non DRM books have not caught the "disease" despite close proximity on my computer and/or reader(s).
As consumers we are lucky compared to students, many textbooks come with a limited use license (time restrictions) and are very expensive. If a student wishes to keep a book for reference or God forbid, has to repeat a course, they are far better of with the paper copy.
Imagine if your doctor told you that they cannot diagnose you because their reference book had expired
Helen