I’ll give it to you that rushing to 60 can skip a lot of awesome content, but there are also endless things to do at 60 just like there are as you level. There’s a lot more to the endgame than just raiding, and having a 60 allows you to do a lot of things with your other characters that would otherwise be impossible. I personally wish more people would put time and effort into low level content, but I also 100% understand why people are loathe to miss a raid lockout.
Raikan - Night Elf Druid
Keatts- Human Rogue
Grobbulus - US
Regardless of the tryhard nature of the state of the game these days, raiding does become more expensive later on. Naxx requires specific consumes for multiple bosses. Those that tryhard must spend more and those that don't actually have to spend. It is definitely useful to have a bit of a nest egg to help with the burn that happens down the road.