I object to DRM and patents on entertainment as well. (You can't actually patent music and videos, but software is subject to software patents and I do object to those.)

If you're asking why I don't object to entertainment as a class, it's because of practical considerations--there is quite a bit of entertainment without DRM, small scale infringers are much harder to catch for entertainment, much entertainment is not patented, and while entertainment is copyrighted, it does not normally copy itself and copying is not a routine part of how one uses it in the same way that producing and saving seeds is of using seeds. Furthermore, pretty much all GMO organisms are produced by large companies who encourage DRM and patents. There are plenty of producers of entertainment who have no interest in such things, even if they do end up using DVDs with CSS.