I think how that comment would be taken is pretty dependant on audience. Some ministers do need a kick in the pants about self-discipline and organization when it comes to sermon prep. But if you are labouring as best you can for God's glory, you might need more encouragement than a "giddy up".
I read it. I'm narkey too. It sounds graceless and judgemental. I have met very few ministers who need a kick in the pants with regards to sermon prep. Yuck.
In fact, I would like to go on over to his blog and tell him he needs to humble himself at the foot of the cross.
I think its entirely fair to feel narkey - there are a dozen other things the minister has to also do well, and most ministers probably feel quite isolated, and panning the lot of them for bad culture seems like misjudgement to me. The problems he is complaining about are very narrow. It almost seems he's wanting to just excel and preaching and excuse himself from the other, messier tasks. I think part of the difficulty is intrinsic in the pattern of having a minister. At our church, I greatly respect and appreciate our minister, but what I love the most is the admin he has done. He has helped sell off our second site, halving the amount of nugatory maintenance and administration and utility bills and worrying about who's renting it and how they're behaving. (I would really like to get a full time administrator next time, because when I try to do admin, it goes badly, and the requirements for compliance from both the government and our super-structure are growing more and more onerous. I'm going to end up going to jail because I can't complete paperwork on time.) But people only have so much experience of grace, so much repentance and faith, only so much ability to be the model, and the job of preaching should be shared around (I think) more than the 'ordained minister' model ... allows? expects? Choi (a friend) reckons once a month is a more fair expectation.