The motivation for this is that some applications are unaware
of this feature and can set their volume to 100% on startup
harming people ears and possiblly blowing someone's audio
setup.
I noticed this in #54594 and by extension epiphany[0].
Please also note that many other distros have this default for
the reason outlined above.
Closes#5632#54594
[0]: https://bugzilla.gnome.org/show_bug.cgi?id=675217
dc923b6ad1