I agree, I'm a BFS guy, too (I like that word, very good description). This behavior is a major PITA. With the introduction of JS frameworks in all kinds of cases (e.g. static blog generators that use react), there's the possibility that the developer messed up the routing or deep linking or even forgot the whole feature because he never opens links in new tabs. I have the presentiment that this will happen a lot in the future.

Even m.facebook.com has this problem in the event overview. There's no way to open nearby events in a new tab because the link only works due to JS hooks.

If you're implementing links with a JS onclick event of some flavor, instead of an <a href="...">, you should be hung up in the street by the toes. There's no excuse for making things more difficult on yourself, in a way that breaks the way things are supposed to work.