People who don't have a room for a 10'x10' desk but have ample room for drawers? I'd say that for a lot of people, constant access to other windows and constant re-arrangement (whether manual or automatic) isn't a big issue, so elaborate positioning constraints are barely an improvement over alt-tab. The primary solution for both kinds of users who need to keep several sets of different windows seems to be virtual desktops (or "tags") anyways, whether it's tiling or not. Moving windows between sets is rare enough...
And then you've got the problem with in-application windows, e.g. Firefox' tabs or vim/emacs buffers or tmux/screen windows. Yet another nested set of layout methods, constraints and shortcuts.
Which is why I fail to see it as inherently better, just like there's nothing wrong with on-desktop icons or scrolling desktops. Don't get me wrong, I'm using i3 myself, as the grid/stacking nature makes for some convenient keyboard shortcuts and I'm fine with the looks, but I doubt that this saves me a lot of time compared with my previous long-term staple of lwm...
But yes, the cargo-culting is pretty annoying. Ncurses apps aren't that minimalistic (esp. when you hear this from late-game Plan 9 fanboys), and if your screenshots are just a bunch of music players and IRC windows, I doubt any claims of huge productivity gains.