You are not. :) I don't usually use full screen mode for apps when my Macbook Pro is docked, but when I'm just using the laptop screen it's ended up being surprisingly useful. (At least I was surprised.) Docked I'm usually only using two virtual desktops, sometimes three.

Mission Control gets slagged on more than it deserves -- it's fast and functional. On point for the actual link to Amethyst: I use Moom for window resizing/control from the keyboard, but in practice the mouse is actually pretty darn efficient when what I want is to make a window this big and put it over there.

This is pretty much how I use my favorite tiling window manager on Linux: i3.[1]

There are occasions when tiling features come in handy, however (such as when you want to see more than one window at the same time).

[1] - http://i3wm.org/

I do this with trackpad swipes and a grid of desktops (using TotalSpaces2 currently). Each app or task has its "place". I've tried other stuff, but the spatial metaphor really works for me.