Really, you start with "Those days are long gone", then talk about "letter-sized printouts at 10 characters per inch"?
To me, 8 is just perfect when viewing on a computer screen, it has the perfect balance of clarity and horizontal space management. But if someone thinks it's too much, that's fine - because I'm using tabs, so they can reconfigure. This is where all the anti-tab arguers shoot themselves in the foot. There are some good arguments against tabs that make the spaces vs. tabs choice non-obvious, but seems like noone on this thread has a clue about these.
(Of course, in Python I just follow PEP and :set et, tw=4, sw=4. A whole-ecosystem convention trumps personal preferences, and Python especially (with its semantic indenting) has good reasons to abolish tabs.)