http://www.fangraphs.com/leaders.aspx?pos=all&stats=sta&lg=all&qual=0&type=8&season=2014&month=0&season1=1992&ind=0&team=0,ss&rost=0&age=0&filter=&players=0
There has definitely been a shift since 1993.
K/9 is up almost two per nine innings since then.
Hitters get on base much less and strike out a lot more (not just due to bullpen specialization either.... pitchers are either much better or hitters are a lot worse.... probably the former).