It is just dumb. Complete disregard for safety and security.

Rating: 4/10 (20 May 2017)

Apparently films don't exist in the future, so none of the crew has seen a horror movie. It seems every single stupid decision people make in horror films is in Alien: Covenant.
Just for starters, here is something we all learned a long time ago from watching the first Alien: quarantine. If you're on an alien planet, and an alien organism infects one of your crew, don't bring that crew member into the ship. Isn't there a Ripley on board, someone with common sense?
Another lesson from Alien and its James Cameron sequel Aliens, if you see something that looks like alien eggs, and one opens up when you approach it, back away from them, shoot them all, burn them, destroy them. Don't go in for a closer look.
And if you're on an alien planet, with alien wildlife and plants, bacteria and viruses, maybe you shouldn't poke things, or go off on your own. Maybe you should wear a breathing mask, and take other basic precautions, so you and your crew don't infect something or get infected.
Why? About every ten minutes I was whispering that at the screen. Why do that, it's stupid.
Another lesson from practically every robot movie: be careful of self aware intelligent machines. No one in Covenant got that memo.
Don't give the villain who has been trying to kill you, who thought he had killed you, time to regroup and regain the upper hand. Don't engage him in a conversation just before you're about to finish him. Don't let him make a speech, as he buys time while searching for another weapon.
Safety checks, quarantine? No, let's ignore all of that until it's too late and people die. Just dumb.