tab spacing isn't just "used to it". It's the "hidden white space has meaning" problem. Copy and paste some code indented with spaces into some that's indented with tabs and if you're unlikely they'll look like the indentation matches but the won't actually match. If you're even more unlucky the code won't just crash it will appear to run but the result will not be what you expected.

You try to get around it by using an editor that shows tabs or an editor that re-indents the code but plenty of editors (notepad, nano, vi, emacs) don't show tabs as different from spaces by default.

https://wiki.c2.com/?SyntacticallySignificantWhitespaceConsi...