You are aware of his prior injury history right? Why risk it in having Ryu throw an extra 15+ pitches and potentially be taken out midway through the inning. We'll get 100+ pitches from Ryu when we need it, no point to it in this game.
92. I think it's pretty clear from every Ryu start thus far that either they're easing him into the season or babying him due to his prior injury history. It's not the playoffs or a particularly decisive game, I don't see the issue with taking him out after a solid 6 innings when the bullpen has been fine and you get to rest his arm for when you really need those 100+ pitches.