If you tab twice and delete once with tabs, you've indented once.  If you tab twice and delete once with spaces, you're (tabLength - 1) more backspaces away from being indented once.  Tab thrice and you're (tabLength * 2) - 1 more backspaces away from being indented once.  That's a pain.

More easily, reverse operations with spaced tabs bork.

With apologies to Thomas: Every keystroke is sacred.  Use tabs.  QED.

Labels: