S-E completely axed their music division and everyone they get now is freelance, iirc. Yoshida worked on how many main series FF's? Very few. Unless you count FF3 remake, FF4WOL, BD, FFTA, FFTA2, to be main series.
So he's only really got FFXII and XIV under his belt, and I doubt after XII and XIV - both colossal fuck ups in the production end - he'd want to do it again.
Plus, as Oscar said, Yoshida was one of the few remaining guys left from the original Quest team. Those were his bros.
Amano has done a lot of work as a freelancer. Yoshida can and will likely carry on the same tradition. That's why it's distinguished mentally-challenged people are raging: because this is good for everyone EXCEPT Square. Gamers get more games with pretty Yoshida art, Yoshida gets to do his own thing and likely with old cronies again, S-E still gets Yoshida action when they want to.