For me, it is all about the user experience. With dvds, there are some where I did circumvent and copy to my hard drive because they are workout dvds and either a) I want to play one section of one, one section off another and am too lazy/don't have time to keep swapping disks and going through menus etc or b) they are workout dvds and have long warnings/ads which cannot be skipped, and I only have 30 minutes to exercise and literally do not have time to sit through them. In both cases, I am wanting to engage in legitimate uses for legally purchased media I own, so I see no problem with circumventing. But of course, it would have been easier if this had just been 'allowed' from the outset.
Ditto with ebooks. I want to read them on my Sony. I had past Fictionwise purchases which I could not read on my Sony because they were in eReader format. I wanted to buy future books to take advantage of the sales. If my Sony would accept secure eReader files, I probably would not have bothered to remove the protection. But they do not accept eReader files so I had to remove it and convert them. Again, these are my legal books I bought and paid for, so I see no problem. But they did lose some future sales by insisting on the DRM because I find the conversion process a bit tedious and will only suffer through it for books I really, really want
I would buy more books if they were unencumbered and I could read them where and how I wished to. Many more of my purchases now are the multiformat books. I go for those when just browsing. I only buy secure books if it's a best-seller I simply must have