indent-tabs-mode default [was: Representation of the Emacs userbase on emacs-devel]

[Drew Adams <drew.adams@oracle.com>]

I'll just mention this reason that `indent-tabs-mode'
should be OFF by default "nowadays".  It's a reason
that wasn't so strong in past years, I think.

With it OFF, code copied from Emacs (vanilla, 3rd-party,
or just code someone tossed off in *scratch*) and pasted
into online forums (StackExchange, Reddit,... whatever),
or emails (not necessarily plain-text), or applications
won't have its apparent indentation changed.  That's a
good thing.

I see this gotcha a lot on emacs.StackExchange, for
instance.  A user copies and pastes some code, and the
indentation is broken (but maybe not super noticeably),
because TAB chars are used here & there for indentation.

That means the user (or someone else) needs to then
notice that apparent change (gotcha), and then edit the
code to give it reasonable indentation.

Even a user (such as myself) who's aware of the gotcha
needs to, e.g., use `M-x untabify' before copying, when
using `emacs -Q'.  Some users don't know `untabify',
and they end up doing the TAB-at-a-time editing outside
Emacs, in the paste destination.  That's a shame.

This is a small reason, perhaps.  But it is one more.
It's an unnecessary bother, IMO.

It's easy enough for some local use (e.g. following the
standards of some organization) to customize the option
to ON.  But that should no longer be the default, IMO.