[1] only gripe I had with XUL was the use of rdf for backend data representation
I also thoroughly enjoyed that era.
My problem is Mozzarella keeps removing Firefox features that Chrome adds later
Google's decision to have crippled extensions was made in a corporate board room to maximize Google's leverage at the expense of utility for users. So it is tragic and baffling to see Mozilla pantomiming what Google did, since throwing away a far more mature and powerful extension framework benefits nobody but Google.
Google could troll Mozilla by just announcing that they are deprecating local bookmarks (and they may very well do that), and watch as Firefox obsequiously removes bookmarks from Firefox, "to stay modern", and then Google could pull the rug out from under then by not deprecating it.