Come on man, even you are better than this. Who gives a f*** whether Kikuchi was bad last year. Your argument is similar to saying Manoah should be kept in games longer because he was good last year instead of taking into account how he is actually performing this season. Kikuchi is a much better pitcher this season than he was a year ago. His stuff is better and his command is much better. His numbers third time through the order this season are much improved vs over his career as well.
When he's dealing against a weak lineup, has ace like stuff on the night, is commanding his pitches effectively with minimal mistakes, accumulating whiffs, has shown no sign of fatigue either with regards to stuff or command, pulling him in the 70 pitch range is an extreme example of over managing. The Mariners did not look dangerous against him the entire game, and most of their baserunners up to that point were softly hit infield singles.