Their best players are 28 and 29. So, again, end of their window. Best players are either leaving or getting really expensive as they hit their decline years, they have some bad contracts on the books, their farm system is shot (and the contracts are so bad that they can't re-stock it). Therefore, that's the end of the window.
And, yes, I am that dense. I blame the bad pitching more on Francisco Liriano being likely the worst pitcher in the majors and Gerrit Cole being injured.
If you're replacing Nicasio and one other pitcher with 2 of the rookies, Cole is healthy, and Liriano is even pitching at 2014 levels (his worst year here), the rotation is far better to date -- or at least more palatable since any struggles would just be the usual rookie scuffles.