Well, Subspace Emissary while not perfect (it has pretty bland levels and not so great level design), it was still something cool, and a good attempt of a campaign mode for the series. It did somethings right, the cinematics and boss battles are pretty cool, and only having all these characters united fighting against a common enemy is something that felt special. While failing in being awesome, it was great enough and it showed that, maybe with more care, the Smash series can have a side scroller fighting campaign with plataforming elements, mixing all these series in some great way.
Smash Tour is a multiplayer experience, that when you start to play with your friends, most of them will just be confused about the super polluted interface with many aleatory things happening at the same time. Also, at least for me, I tryed to play this game with my friends 3 times, and all the times after some time, some of them just starts asking why they are not playing regular battles and having fun instead of a random boring boardgame with these crazy rules that they dont care. This alone shows this mode totally failed in being something captivating.
SE and ST are not perfect, but SE is still good for a singleplayer mode, and ST is terrible for a multiplayer mode. Only one of them is at least partially successful in my opinion.