What was Fitz doing with that briefcase?
When did Inhumans trump HYDRA?
That not only closed the door on introducing other "altered-human" races like the Eternals, they shoved HYDRA - the main purpose for S.H.I.E.L.D.'s existence in the first place - completely aside. So much so that we didn't even get to see Coulson's team finish off HYDRA's infrastructure in any way.
Daisy
After three years of making her a known character...and a badass...they made her evil.
W...T...F...?
Then there's the other crap, such as:
- the ridiculousness of making that Australian dude an Inhuman version of Gambit
- the fact that Coulson's team had a good idea (contacting the female Inhuman) that the baddies beat them to...AGAIN
- the stupidity of Lincoln's suicide vest. Instead of being full of bombs meant to kill him, why not water balloons?
- while everyone's focused on creating a 'cure' for Inhumanism, no one's thought about ways to neutralize their individual powers. I'm not saying S.H.I.E.L.D. has to be Batman, but if something's going around turning Inhumans evil, and you've got Inhumans on your team, brainstorming ways to turn off the abilities of those around you just makes sense. There's enough brain and mechanical engineering savvy between Fitz, Simmons and Mack to make it happen.
Just sayin'...