I don't. I would be much happier buying ebooks without DRM and I would buy substantially more of them if they were DRM-free.
Besides that, a lot of publishers who sell their own books do so without DRM by default. As does almost every book bundle hosted by Humble Bundle.
Yes, not many people know what DRM is but many of the effects are noticed when it ruins their experience.
For me, I bought a single DRM book against my better judgement because it was the only available way to get it quickly at the time. Predictably, I eventually lost access to it and never bought another one since.
And to be clear, I understand and agree with the moral objections to DRM. I think we have lost something more than just the loss of ownership and control. But while you're actually reading an ebook, none of that ever actually affects the experience.
Also, ebooks do support links (I see them most commonly used for linking to chapters from the table of contents, or linking to appendix notes), so you could make interactive fiction if you wanted.
You can also install FFUpdater (either via F-Droid or directly) for a huge range of browsers.
What do you see as locked down?