Not for a technical reason, but they had a reason: they provided no support or guarantee that Netflix would ever work on Linux + FF (Ubuntu + Chrome was guaranteed) and they didn't want any support calls for something that they wouldn't help people with anyway.

A lot of stuff gets blocked for this reason. The company doesn't want you calling them because HD video doesn't work on Firefox even though you pay for HD quality, they do not test or guarantee Firefox compatibility in the slightest and yet they have to talk to an angry customer now. It makes business sense to redirect people to supported use cases when you know your product probably won't work as intended otherwise.

You don't have to agree with the decision (and you can always cancel your membership if you do) but they had their reasons.

Why not a banner saying that it's not supported and may have issues? You might lose customers if you simply block them from using it at all.

> and they didn't want any support calls for something that they wouldn't help people with anyway.

Even knowing what they were doing, I fielded at least two support requests asking what was going on. I can only hope I wasn’t the only one.

Now that everything plays nicely I just happen to have no interest in Netflix for other reasons...