It makes me really happy when forks are merged back together. It's a big success for open source, and shows how differences can be resolved through experimentation and time.
Well, from a user pov I don't think it's good that they have to learn two different ways of using the graphical user interface or that some things are incompatible with their other chosen environment.
From a dev pov I prefer signals and slots over callbacks, but I know that is just a perference.
I don't mind 'competition' among things towards standards. Like web browsers for e.g. chrome, ff, explorer, opera, lynx... Yay. Bring more.
But the bs around linux guis is just that.
@gemlog @maiki agreed. I wish there was more effort to make it easier for developers to write applications for desktop Linux that look great regardless of the desktop environment the user chooses. I don't know how to do that without ending up with the lowest common denominator of widgets a la Java Swing applications circa 1998.