When choosing the default desktop environment, it is important to think of
the main purposes of Trisquel GNU/Linux, and not about personal preferences
alone.
It should encourage unexperienced computer users to try free software
(experienced linux users won't have a problem with changing their DE anyway).
It should be able to use up-to-date free software applications. It should be
convenient. It must support universal access for handicapped persons,
especially at install time(!). It should meet security and privacy
requirements.
XFCE and MATE are unsuitable because the first is still gtk2, and the second
supports gtk3 only experimentally so far. It would be difficult to get
universal access tools working, and they would require to replace a lot of
applications.
KDE can do everything for experienced users, but uses to confuse
unexperienced users.
And then there is the funny fact that Micro$oft forgot to take out a patent
for their most influential invention: a desktop with a taskbar at the bottom
and a start-button in the lower left corner. Everybody who learned personal
computing after 1994 knows this concept. It became a standard by custom.
GNOME Shell and Unity both irritate users because the working environment
"disappears" after pressing certain keys. Again: this is no problem for
experienced users, and not for people who never used a DE before, but this is
not the general case to expect.
The GNOME Fallback solution is really fine. It meets the expectations of the
average computer user. It allows to use gtk3-applications. Replacing mutter
with metacity allows to run it on slower hardware, and metacity is well
tested and very stable. It removed these damn Gnome Online Accounts, but
included the tweak tool and alacarte as standard. It works with screenreader
and universal access tools. What I like most is the behaviour with external
data storage: adding the disk mounter to the taskbar allows to see an
attached device, to mount it, and to open it in separate steps - no
automounting, and no unwanted "disappearance" of unmounted devices. Safe and
convenient.
To choose LXDE for the lightweight solution is excellent, too. Almost
everything can be adjusted according to
http://openbox.org/wiki/Help:Configuration but the default configuration
works fine for unexperienced users.
All in all, the standard configurations of Trisquel GNU/Linux 7 and Trisquel
Mini were really good choices and should be kept in the next release.
I respect all other opinions, but their authors obviously know how to get
what they prefer. A standard desktop environment must be able to attract new
users. We need more users of free software.