Ummm, it's a DRM, not technical issue. The DRM is imposed upon them by content creators. In theory, FreeBSD could get a moonlight port, then try to license the keys used for the DRM, but unfortunately, this is likely a deal breaker for Netflix. Also the FreeBSD project has to do the work, Netflix can't, since they can negotiate a contract on behalf of FreeBSD.
Moonlight is open source. Netflix could port the DRM if they wanted to; FreeBSD would not need to do it. by my read of the CC license they'd have to contribute that back to the project, but I'd guess they could then negotiate the licensing of the keys; keys are not code so I don't see any more problem with that than using your own keys in e.g. GnuPG.
So few people use *BSD as a desktop that the demand for it is not going to make it happen, however.
