Kawamori has already gone through that personal divorce from the series that made him famous.
Even Macross II didn't shake him out of that funk.
It wasn't until the studios wouldn't give him the money to make his Top Gun in space story, unless it was in the Macross universe, that he accepted the fact that he had leverage with Macross and could use it. Thus Macross Plus was born.
That may be the reason why we don't see as many Macross productions as other series, in that if SK doesn't have a Macross story that interests him, he doesn't persue / develop it.
I do agree that it couldn't hurt for him to collaborate with other story tellers, with respect to the franchise. Such partnerships tend to find fresh angles to tell stories from.