This isn't due to transcode issues. They use Silverlight to stream to full-function PCs (be it OSX or Windows). Microsoft hasn't made Silverlight available to the greater GNU community, so it's pretty obvious that they wouldn't distribute to Linux: their contracts with content-holders probably hold them to constricting DRM demands on the videos streamed to devices capable of ripping them off.

Don't blame Netflix for it. Blame the arduous contracts which must be negotiated in order for Netflix to carry the content it does.