There was 13 pitchers in the top 50. Thats the first 4 rounds. While pitching is harder to guess at guys like, Santana/Sabathia/Halladay/MoRivera are always in the top 50. You take players like Sizemore/Reyes/Holliday in the first 4 rounds because you know they will produce. Well to me the same thing applys for pitching. If you know they will produce why not grab them?
Because you don't know they will produce. For every Santana there was Carpenter or a 2006 Peavy etc. Also in H2H pitching just isn't as valuable. In weekly leagues you go with a lot of 2 start guys which somewhat devalues single start guys and in daily leagues people stream pitchers which completely destroys the value of single pitchers.
I wrote a post last year showing the top 20 pitchers according to cafe rankings and how many of them repeated the next year and the number was a fraction of what the hitters was. Something like 40% of the top 20 pitchers wont' finish top 20 at the end of the year. Something like 20% won't even make the top 50 because of W variation, ERA spikes or injuries.