The challenge came when there were devices which operated incorrectly when presented with a TAB character or confused command data with actual data. That became the "killer" issue when computers started substituting for typewriters. Because a typist knows that if you hit the tab key the carriage would slide over to the next tab stop that was set on the platen bar, but the paper was "all spaces". When you try to emulate that behavior in a computer now the TAB becomes a semantic input into the editor "move to the next tab stop" rather than "stick a tab in" and "move to the next tab stop" could be implemented by inserting a variable number of spaces.
Computer engineers knew it was "stupid" to try an guess what you wanted with respect to tabs so they wrote a program for formatting text called 'troff' (which had similarities to the program on RSX11, TENEX, and TOPS called RUNOFF.
It is always interesting to look back though, if you had told a system designer in the 70's that they would have gigabytes of RAM and HD displays in their pocket when their grandchildren came to visit they would have told you that people always over estimate how fast change will happen.