The thing is, it wasn't an act of stupidity - on behalf of a supposed expert - in isolation. There were a lot of things being done by all of them, which, taken all in one go, kept hitting the audience over the head with how recklessly nonsensical these individuals are. David 8 touching everything in sight, Shaw's other half removing his helmet and contaminating the site, Fifield not having a f**king clue about the status of his own mapping system, etcetera... All of it happens within a relatively short space of time of one another.
It wouldn't have mattered as much if they were just random people, but they're meant to be such leaders in their field (and Milburn, specifically, is meant to have much experience with living organisms and all the scientific protocols of handling them, thereof), that they've been individually head-hunted to go on a potentially one-way trillion-dollar mission of the utmost importance.
Ultimately, we're left with the basic impression that they're all so idiotic that maybe they don't deserve to survive and lose any would-be sympathy for them. The very connection you don't want the audience to lose when it's something as tense as the horror genre.