Parallel Earth: Oh, kind'a weird. Oh well. WHAT?! In "Miri," the most interesting part of the episode was the parallel Earth, but people just shrugged like is was a Tuesday or something. How often does this happen on the show??? Why is it never addressed again on any of the spin-off shows? Seriously, I want to know why parallel Earths is a thing, why it seemed to be used often on TOS, and why it doesn't exist beyond TOS/TAS. I need to know. WTF is up with parallel Earths? I know budget is the real-world answer. 
