Well, you never have to, but it can be useful, e.g. with C-M-x instead of M-x eval-defun RET. I've never yet had to bind a chord with more than two meta keys, b

Well, you never have to, but it can be useful, e.g. with C-M-x instead of M-x eval-defun RET. I've never yet had to bind a chord with more than two meta keys, but considering that even Photoshop has three-meta chords (e.g. C-M-S-s, File/Save for Web...), I don't really see the problem.