It was the obvious choice. I know Robin & Patrick are a forever couple, but if KMc isn't coming back on a regular basis, you've got to do something with the character. He's one of the romantic leads of the show, why not pair him up with someone he has history with? And it would be automatic conflict for when Robin returns.
a lead. Not sure where you got the idea he's a lead of anything.
Why not pair him with with Maxie? Cause she's Robin's family & JT/KS have no sexual chemistry.
And if you have to do something with the character it doesn't have to be in a romance.