For me, the problem is I have to alt-tab to get to the right window, pause, remember that alt-tilde exists, alt-tab to get to the right program, pause, alt-tilde to get to the right window in that program.

I've only got a half-dozen or so things open. For me, it's just faster to have one shortcut (alt-tab) let me cycle directly to what I want, instead of having to bounce between multiple shortcut commands.