These days, even those options are gone. You can’t sell it or install it in any normal way if the platform vendor doesn’t like it. You will even need to “notarize” side installs (which will kill truly free software because no one should need $99/year to distribute what used to be free).
And the only thing worse than all the rules is the brutal inconsistency of it all. Had this person lucked into one of Apple’s “meh, sounds fine, Approved!” reviewers, there would have been no rejection and no blog post. It is really a crap shoot, where lots of crap gets into the store too.