Didn't you just dismiss Plassmeyer a couple of months ago after I noted he had a good start?
For the record I never dismissed Irvin. Always thought he was useful and could have developed into a back of the rotation starter but also recognized that he got caught up in a roster shuffle and they really had to move him (traded him for cash instead of losing him to waivers).
It is the reality of today's 40-man roster which is increasingly squeezed by the number of pitching injuries and the increasing roster size. The fact is, Plassmeyer being likely to pass through waivers made him a candidate to be called up even if he was there just to pitch multiple innings if they got way behind.
Nobody is "dismissing" Plassmeyer. We just realize where he is compared to their other pitchers and knowing that they made this move simply because he is "behind" those other pitchers. Optioning a pitcher means not having them for 15 days. We might want Appel or Morales up for longer periods of time than Plassmeyer if they get called up in the next couple of weeks.