Depends on what you want out of it.

For myself, I am ok with skipping during the leveling process if they are going to slow your progress to 70. You can always go back and do it at max level if you need an item from it. I don't farm them for misc stuff, that is incidental to the process and right now only serves to fund my 5x epic flying expenditures.

Ultimately, I am aiming to be able to clear all of the HC content, bring my team where it is needed for guild raids (so I'll need to do all the attunements), and ultimately exceed what I was able to do back in the OG TBC.