Honestly I do believe it's more thanks to how they've made the expansion this time. From 90 to 100 goes quite fast even by doing only the Draenor quests. And then as lvl 100 what is there for you to do? Pretty much only raids or BGs. The Apexis daily isn't like the dailys we had in MoP that actually gave you something. The Garrison is a nice feature but I don't want to spend the rest of the expansion in mine.
The only thing I now do with my lvl 100 toons is running old stuff that I never got to so I can get some transmogs and perhaps achievements to get a mount or two. And after a while that gets boring too as the stuff you want never drops anyway.
I know WoW have been around for 10 years now and I can understand that the devs wants to try new stuff and change things to see how it works out. But some things should not be taken away. Right now the game is getting a bit boring as I wait for something for my lvl 100 to do except run around their Garrison picking herbs or mine.
Yeah I should stop playing if I don't fun the game fun anymore. Well in one way it is fun as I got my friends there. And leveling a new toon from lvl 1 too 100 will probably be fun too. Hopefully when that toon is lvl 100 there will be something for her to do except stand in her Garrison and look pretty.