> It seems that everyone went Gtk because Gnome was the default DE for most major distros.
No, the problem was with Qt itself. The whole reason GTK was created, is because Qt wasn't really FOSS. Only much later Qt was really opened up. So yeah, today Qt is open and it's clearly much better. But the damage was already done, and the split happened.
Qt has been open source since 1999 and GPL-licensed since 2000, nearly 17 years. GNOME was started in 1997 and GNOME 1.0 was released in 1999. So, much later is not really an adequate description.
I think the grandparent is definitely right. A lot of projects were started post-1999, when Qt was already open. But GNOME was the default desktop of many distributions (including Red Hat and later Ubuntu). Moreover, it is harder to bind Qt in order languages, since it is C++. There was a strong dislike for C++ in parts of the FLOSS community.
Not much, but 2 years were still enough to cause a major split and kick off Gnome / GTK and push the later from an obscure library used by Gimp to a widely used GUI toolkit.
No, the problem was with Qt itself. The whole reason GTK was created, is because Qt wasn't really FOSS. Only much later Qt was really opened up. So yeah, today Qt is open and it's clearly much better. But the damage was already done, and the split happened.