I dunno, I don't buy most of these reasons. I think the 4-2 win where Torreira scored was as impassioned as any NLD I've seen.
Still think it's mostly just about circumstance and long term competitiveness, there hasn't been anything to spark a rivalry for a while. Liverpool and United for example has been dead since I started watching football. Arsenal-United on the other hand really kicked off despite mostly being a modern invention. You had Liverpool and Chelsea for a bit under Rafa and Jose.
You have that less now because it's generally much harder to stay at the top, managers come and go quicker, players come and go etc. But I don't think it's a thing of the past, you just need a spark.