Re: magic-mode-alist gets in the way

[Richard Stallman]

    > It can't be that hard to copy the code from the
    > definition of
    > magic-mode-alist and change the aspect you want to
    > change.

    Actually, it may be be unexpectedly tricky because it
    would require knowing what the backquote and comma do
    in Lisp, something I only learned after working on
    patches to PSGML and ispell.el.

It is not very hard.

     It also requires
    learning where magic-mode-alist is defined,

Use M-x find-variable.

    Also, many distributions by default don't
    install the .el files for Emacs, only the .elc files,

Please complain to the makers of those distros.

    Also, the case has not yet been made for why a unified
    auto-mode-alist is such a bad idea.

Yes it has.  You may not be convinced, but that's a different matter.

    The objection that
    I've seen so far is that the entries that match by
    file content would be unknowingly overridden by the
    entries that match by file extension,

Yes, that is the problem.

                                          but that isn't
    always a bad thing, nor always what would happen.

Those two statements are correct, but so what?
The problem is still a problem.

It is the same kind of problem as the one you are complaining about,
but bigger.  You're saying it is tricky to customize when you want to
override magic-mode-alist.  However, with the change you want, it
would be tricky to customize when you DON'T want to override
magic-mode-alist.  Not impossible, but hard.  People would do the
obvious thing and it would not work right.