I think there's a tremendous difference between falsehood and matters of opinion.
When one looks at the ratio of PA that end by the pitcher (K, BB and HR) vs. those that end by the defense (balls in play,) one finds defense to be a pretty big part of the game.OPS and its elements are the result of many factors. Defense and luck are definitely some of the factors, but they are by no means even the most important or driving factors.
Some days, you have Scott Rolen at 3B and some days you have Todd Frazier. One year, you have the 35 year old Rolen and the next you have the 36 year old. Sometimes, a ball in play is a "Texas leaguer" (my favorite baseball term) and sometimes it's a weak flyout to an infielder on the outfield grass.
And this isn't even getting into field condition, defensive positioning, etc.
The other problem is OPS itself which to me, overstates HR and 3B.
It's possible to measure pitching in isolation. There are a variety of ways to do so but it can be done. I think it's reasonable to suggest that Homer is pretty much the same pitcher regardless of the situation.
To me, defense independent stats are more solid.OPS is a very solid way to evaluate a pitchers effectiveness.