[tdicola]

If you really want the window manager to handle your browser windows then just open new windows instead of opening tabs. All of your window manager's fancy window switching features, etc. will work.

[tatterdemalion]

I think the problem isn't that tabbed browsing exists, but that window managers are not good enough to handle user experience as well as tabbed browsing does.

[rspeer]

And the fact that tabs exist isn't stopping window managers from getting better at it. They just haven't.

It seems that putting the application in control of its window-switching experience has just worked out better.