Yes, I agree. Trisquel's main purpose is to create a free Ubuntu rather than
merely an "easier Ubuntu" and no other distro has done that on an Ubuntu
base. But you see Mint, Pinguy, AriOS, BigLinux, moonOS, Super OS, Zorin n'
stuff are nothing but Ubuntu preinstalled with PPA's and proprietary
software. They do the same thing with a different interface. Mint at least
has some software developed in-house, the others are just plain Ubuntu with
tweaks. I don't think there is such need for something like that. If you
don't like Unity or Gnome Shell, tweak it yourself or use Kubuntu, Lubuntu,
etc.
Another disappointing story is Sabayon. I have read the leader's biography
and he said Sabayon came out of a bet he made with a friend that said nothing
good could come out of Gentoo. What the heck?
And yet another reason is, some distribution can't keep up with the pace of
the parent's distribution and are way several releases back (BLAG,Venenux) as
an example). There are also distributions marked as "active" in DistroWatch
with last release being in 2007 (TurboLinux as an example). So I always tend
to go back to the roots and use an already established, long lived but most
importantly, a regularly released distribution.