Nintendo's store is the only one available on a Switch. That is almost a congruent comparison.
Perhaps, yet despite that the Apple app store is considerably more open in almost every other way.
Do they skate because users can pay more to get a version of the hardware that has that capability?
For this argument to participate we have to assume it implies that people could develop, compile and deploy Switch games to commodity memory cards and then install them.
Otherwise it is the same behavior, from the perspective of prohibiting competition.