Anyone who ever served in the military wouldn't think that was harsh at all.
Afghanistan is a quagmire and something has to change. This may well turn out to be a Petraeus-for-Casey kind of swap, and if that's so then Gates and Obama will deserve the credit. If it turns out to be a mistake then they'll deserve the blame. But regardless, the troops in country deserve our hopes that McChrystal has the same kind of positive impact on the war in Afghanistan that Petraeus had on the war in Iraq.
Casey didn’t get fired, he became Chief of Staff. Even if McKiernan needed to be replaced there was no reason given for his forced retirement. If the new guys came from the Pentagon then there were slots open that GEN Mck could have filled. There is way more to this story than is being told.
McChrystal and Petraeus are cut from the same cloth. Force multiplication through intelligence is the special forces way. Combine the intelligence you get from the special forces way, with the firepower we have developed during the 20th century and you have something that is much more effective than the firepower alone reacting to enemy initiatives.
The goal here is to not blow away the enemy AFTER you walk into his ambush, but take out the bad guys while they are moving, assembling, or planning. Kiernan was an armor guy and the mindset has its place. Afghanistan is not the proper place for a man trained to deal with mass armored warfare. Don’t forget — Petraeus endorsed this change.