And there's more to it than that. TTG never went out of its way until fans completely mistook it as some kind of continuation of regular TT(when it was never such a thing) and basically insulted the staff and such. They literally just responded equivalently overall. It was an insult-fest. This still stems to the fans being completely unreasonable and refusing to accept that spin-offs are fine. You can dislike the show without being an ass about it, which a good chunk of the fanbase was.
Of course the response was wrong too. They were both in the wrong.
This is going to continue to happen as long as the fans act immature about the situation. People get fed up with their work being unreasonably dissed after a while. I can't blame the staff whatsoever for their response. It's a show. It's not one you overall like. That's fine. And the staff did go out of their way to make it clear it's not a continuation anyway, so the fans really don't have an excuse anymore. Refusing to do any research so you can act inappropriately? That's their fault too. The worst the staff did was respond in a similar manner. Which they should not have, obviously. Nobody gets a free pass for immaturity, really.
Sakurai isn't choosing the characters, Snake. Nintendo is first and foremost. If they think Dr. Coyle is the best option, then yes. If they don't, Sakurai is going to make whoever they choose the best possible.
I agree if Sakurai was choosing, he'd go for someone fairly unique but important. So a key protagonist or main character or a key antagonist. (Main character would count for villains too, I.E. Soul Calibur's Nightmare, who has the best chance of SC characters to get in if Sakurai is choosing. Nintendo might not see it that way, since it's not their own game either. So whether mascot ultimately matters or not isn't the full story. Though then again, mascot seems a reasonable choice due to recognizability. Hero at least had the factor that he was already decided upon by Sakurai to be added during base game, so Nintendo could easily see value in that. And Luminary also represents the latest DQ game to be released, which gives it more promotional value that the series' mascot. Business and all).