The only possibly shady thing you point out is that it's opt out, I get that. Especially people who want to block everything unconditionally might feel cheated because it's not called Adblock Minus.
What Mozilla did here, OTOH, I find shady because they're pretending to run an impartial addon store, when in practice some guy who wants to promote a specific extension (maybe that person feels like you, maybe he's a friend of gorhill - I have no way of knowing) can pull these kind of tricks.
But I suppose it's a case for Hanlon's Razor: They probably just don't have their stuff together about running any type of store the way the big guys do.
I'm still a proud Mozillian, I can find one thing they do shady without finding all of Mozilla shady, I realise it didn't sound like that above.