First of all, this might seem to be mostly a rant about KDE, but I think it is not (at least partly :) ).
But it is, for sure, criticism, and, of course, my very personal opinion (I am not in any way a representative of any of the mentioned projects, just a user/contributor - more or less). So, what's going on in the KDE world ?
In short, these are the most important activities:
In 2008, KDE4 was started as the successor to KDE 3.5, with massive changes to the underlying software stack, not just porting to qt4.
First to mention, the new desktop shell: plasma, with radical changes: no more 'Desktop' with Program icons, Plasmoids instead of traditional Applications, new control widgets ('Cashew') and so on... But with all these changes, and their problems (which are quite normal in the development cycle of huge projects), it was more and more obvious that many users would not want to follow the directions given by the developers anymore.
To sum it up, there is now a clear demand for a lightweight, simple Desktop, based on technology already known (qt libs), but without the mandatory need to have more or less powerful hardware, and (at least) the option to just not install/run memory/power consuming services simply to be able to run a web browser or an email client.
And, of course, there are also (few) developers who share this opinion, and thus, we can now find at least 2 projects to follow the mentioned goals: trinity and razor-qt, both taking a different approach, however:
while trinity stands in the direct heritage of KDE 3.5, trying to keep as much of this experience alive as possible (including the underlying qt3 framework), razor-qt follows another paradigm: provide a clean, slim desktop based on qt4, following widely accepted standards (xdg) without all the load something like plasma/akonadi/nepomuk etc. bring in addition.
This doesn't include a native set of applications, however - it is up to the user to decide which ones to add (and thus, which additional dependencies/frameworks to pull in - might end up with nearly a complete KDE4 desktop installed, though ).
The stunning fact, with these projects, is that for the first time in the KDE history, there are now 'forks' which aim to users who are not satisfied with the current direction of the project. The interesting thing, now, is how these 2 projects are perceived in the KDE(4) mainstream, especially developers.
With razor-qt, there seems to be not very much flame-wars, at least not widely visible.
As for trinity, see e.g. this:
Pro-Linux Article (german).
KDE4 developers however, seem to be rather upset, that anyone 'dares' to fork what they, appearantly, have dropped back then in 2008 (when KDE4 still was far from beeing usable in any respect) as if it were some piece of radioactive plutonium or thelike.
Anyone interested in this subject may just read Martin Grässlins articles/blogs:
Freies Magazin Article (german)
the-grass-has-always-been-greener-on-the-other-side-of-the-fence having-a-look-at-the-oldnew-desktop-environments or also the trinity list archives:
trinity-devel.pearsoncomputing.net (threads 'trinity coverage', 'poll' ...)
nwhere also Aaron Seigo's statements can be found, who obviously avoids writing something on the subject in his own blogs - looks like he wants to avoid any publicity on trinity, presumably.
So, while I do not want to comment on the more technical argumentations in the cited sources, it seems to me that the KDE4 developers just can't stand nor tolerate the fact that there are still users (and developers!) who prefer that what KDE3 offered: a fast, snappy Desktop (even on older Hardware) with a complete (though, with some respect, outdated) set of applications, without all the recently added 'bloat' ;-) .
As a conclusion, simply time will tell wether trinity and/or razor-qt will survive (I personally hope so), and what direction KDE4 will go.