Wow that's a lot of time. And this is for a game that was developed in 2012 with PS3/360 level of hardware in mind.
Well considering that the game has added content, higher native resolution, and a more stable fps than those consoles (as all last gen ports do on switch), 9 months is not really a lot of time.
Your Switch sales prediction was a bust, accept it. No need to grasp at staws trying to downplay the system. You are only hurting your own image.