I very rarely re-read, but I still find the topic of DRM important. My reasoning is I don't want to lose access to a book I've bought but not yet read just because I decide to change my reader to a better eInk device or the company I bought the books from has gone bust/closed their DRM servers so I cannot activate on a new device. It's a little less important for me with fiction books that it is reference or software/music/games where I do re-read/watch frequently.
In reality, DRM doesn't impact me as I only buy products I know I can strip as soon as I've bought it. I only started buying from Amazon because of Alf. So it's more in principle than in practice that I object to DRM.