> Kobo's store does have DRM, but it's easily bypassed by Calibre

See, but that's not actually the same thing as DRM-free. It's adversarial interop that's temporarily allowed to work, but if said interop becomes popular enough the publishers will force Kobo to fix it.

At this point I'm really only interested in spending money on books that I can actually own—either physical copies or (where available) fully and legally DRM-free ebooks. I want my purchases to send the right message to publishers: that DRM-free can work.