Nobody goes to Arzest expecting Super Mario Odyssey, they go to them because they do a project typically on a decent budget and get it out the door on time, pretty much always in a functional (if unremarkable) state.
It's not like they're only involved in complete duds, they (as either Arzest or Artoon) have worked on decent ports and even some parts of good original games including: The Last story, Yoshis Wooly world (3DS port), the streetpass app for the 3DS, the Giant battles for some of the mario and luigi games, Yoshis Island DS (Which is far from a terrible game, the 810 metacritic it has is pretty much right).
Of course, they also have a significant list of duds, nobody is going to deny that.