bug#20322: 25.0.50; indent-tabs-mode should default to nil

[Eli Zaretskii <eliz@gnu.org>]

> Date: Tue, 14 Apr 2015 17:40:17 +0300
> From: Dmitry Gutov <dgutov@yandex.ru>
> CC: 20322@debbugs.gnu.org
> 
> On 04/14/2015 05:17 PM, Eli Zaretskii wrote:
> 
> > Each major mode can (and some already do) have its own default.
> 
> I can see ruby-mode and texinfo-mode set it to nil, which makes sense, 
> but it also makes it harder for the user to configure everything in one 
> place.

But it's simply _wrong_ to configure everything in one place, because
different modes have different conventions.

> > If the customizations are due to language guidelines/culture, then
> > setting this to nil in the major mode is TRT.
> 
> Maybe, but my point is that going by this logic most major modes would 
> need to set it to nil.

I don't understand why.  Can you explain?

> Note that doing that change in major modes will have pretty much the 
> same problem as changing the default: users who got used to the current 
> behavior.

If you only change that in modes which really need that, this problem
won't exist, because, as you yourself said, everybody already
customized these modes to use that value.