I've always been a fan of the Colonel. I have most of his books, and have read most all of them more than once too. While I agree with a lot of what he said, I also know that its all just his opinion, and he, like the rest of us, are not always right. I think in order to be reasonably proficient with all firearms, you need to learn and constantly practice with all types. Not doing so is a major disservice to yourself. If all you learn to shoot well is a 1911, you have only learned one thing. Seems to me, this goes against a lot of the Colonels own teachings or philosophies.
Personally, I think Bruce Lee offered a better solution. Learn as much as you can, about everything you can, and take only what is useful to you from each. Works for me.