Also you said "Either your best resolving lenses aren't as sharp as you think, or you haven't set the camera up properly, or you can't use DPP or photoshop."
Hmmm, if you give 3 options, all of which are user error, then that means you think its user error...no room for movement in your statement sorry.
Once again you misquote, or deliberately misinterpret me. I really tried to give you that 1% out that it may be a faulty camera rather than the more likely fact that you can't work it properly. Especially given that you've went through three.
Interesting that you mention you get on fine with the more basic 40D and 50D which have AF that doesn't require setting up. I thinks me sees the problem maybes. The 7D is really for advance users who are willing to read the manual and spend some time setting the camera up.
Maybe a camera that works reasonably right out the box is your best bet.
I gave three scenarios: crap or faulty lenses, poor camera operation, or poor post-processing. In 99% of cases it will be one of, two of or a combination of all three. See there's still that 1% to let 'those with a dud camera' off the hook.
You also allude to pixel peeping. I'm sure I made it a resolution of mine a few years back to stop debating with pixel peepers.. How did you get on when you shot film? Did you complain to kodak that the silver hallide grains were the wrong shape or not sharp enough, or did you not look at your negaitives through a microscope?
Please don't misquote me again. Go and buy something simple that you can work. The 7D is obviously a rung above your aspirations / ability.