Well yeah, if you use a gnome app, it'll look like a gnome app.
In other news, if you use green paint, it'll paint things green.
In other news, if you use green paint, it'll paint things green.
The XFCE folks are welcome to fork GTK to support their own use cases.
Did you know that GTK was a cross platform tookit, even on Windows and Mac OS? Andf you did not had to install GNOME on Windows to use a GTK app, because it was a tooklit for making apps, and GNOME was a project that combine GTK apps, and a window manager to make a DE.
Many apps ported to Qt so I don't think there is a chance that GTK will get a viable fork, Qt will be the only cross platform toolkit