I've worked with this. I've dealt with blackbox player blobs with >100 undocumented tuning variables, and with TVs whose manufacturer didn't really know what worked and what broke.
I wouldn't be at all surprised if some TV manufacturer broke some streaming variant (such as high-bitrate unencrypted smoothstreaming), discovered after a few months, and silently fixed it in new models without issuing an update for the old models.
EDIT: I wouldn't assume that TVs are better at playing DRM. Just from my experience, non-DRM works better (less code that might be buggy). What I'm saying is that once Netflix had a few hundred working devices that worked with DRM, avoiding player bugs became a really good reason to stay with DRM.