Unless one is of the philosophy that Google is not required to support alternative browsers more than complying with (their best interpretation of) the standard

Unless one is of the philosophy that Google is not required to support alternative browsers more than complying with (their best interpretation of) the standard, which is not a philosophically incoherent position. (On the other hand, perfectly reasonable to assert "If the rules say the market leader doesn't have to care about the welfare of others in the market, maybe those rules need to change").