> It wouldn’t surprise me if they just don’t want the testing and support overhead of supporting Firefox, and so it’s easier to block it than let people use it but it might be broken (and they then file a support ticket regardless of if it says “unsupported” etc)

So many companies mistake "support" for "support". You can have software that supports platform X without providing technical support for it when run on platform X. Commercial software companies tend to confuse these two very different meanings of support.