I've seen many Mario level editors. None of them are as easy to use as Mario Maker. The very few that are more powerful are in turn significantly more difficult to use. All of them are almost certainly on the wrong side of legality. Are you also someone who berates people for buying Virtual Console games, insisting they should download emulators?
It's easy to use, it's fairly powerful, it's easy to share, easy to play other people's levels (I think the game would be worth the asking price just to play other people's levels), and it's official and legal. There's your justification.







