TBH I am not big fan of grinding. but Valor/Justice points had good system for me, as a casual player
I play mostly for story +some fun. rarely do PVP and my maximum Progress is LFR/Heroic Dungeons
during Wotlk/Cata/MoP, good stuff was that I could do Dungeon runs. be it Heroic or normal, and LFR raids. they gave me small amounts of currency which I could use later to buy something usefull. it was small progress but was a guarantee that I could gear up a bit be it a hardcore player or just a casual who works a lot and has small amount of time for game. doing a dungeon or two daily was not too time consuming for me.
Hard modes are for players, who want to have harder and more difficult content and who are willing to give more time for their accomplishment. and they deserve it. I have done 0 Heroic dungeons since BfA started. really. I want to, but I am a warlock, and I have not enough time to spend much time in-game. I barely do LFR wings per week