If you feel it is a waste of your game time and sub money, then don't do it. Simple as that. I have recently started farming ATMA pieces and I'm really enjoying going back to all the old zones I haven't played through in a while and doing all those fates I didn't do at the time.
If I ever find myself getting bored in an area, then I just switch to the next area on my list that I need an ATMA from and do fates there for a while. Plus, seeing the 'You obtain an Atma of...' text is a really rewarding feeling.

I think some people get too hung up on the reward for completing something, and forget to actually enjoy the journey that gets to said reward.