I had to figure out how to not render their own shadow, and to disable the "Close" and "Maximize" buttons and edit the Gtk/DecorationLayout property to taste, but I really appreciate the nice simplified menus they bring, and the removal of the bloated menu bars. They are more usable, specially on a small screen when the window is not full screen (on a tile on the side).
I also like CSD when I have to use Gnome itself for the bigger dragging area. Traditional menu bars and title bars is poor UX just to enable certain programming decoupled. Now the the abstractions have evolved and we have widget toolkits and the abstraction is provided without compromising the UX.
I am sorry you got used to that. You may still use KDE or something else. But some of us really like what GTK and GNOME people are doing. I know the noisiest voices are the critical ones, so here is a reminder: there are plenty of happy users that love the work you are doing. Thanks a lot, I love you for making my computer work better every day, and with Free Software!