A lot of the Prometheus complaints seem to originate from the concept that the crew should have been a 100% perfectly professional team that knew exactly what to do in all situations. Given what Weyland was trying to accomplish, it's not surprising that some of the crew weren't up to the job.
Vickers' team was intended to die to hide what Weyland was up to, so the "exploration" specialists that weren't critical to the process were chosen to be expendable and characterized as such. They were stupid idiots because they weren't professional explorers, but lured there by money to fill an gap in the roster. If they had pulled in a completely professional team, Weyland and David wouldn't have been able to get the situation to the state they needed it.
I'm constantly amused by the number of people who get so upset when a movie portrays characters this way. It isn't a failure of the writers, it's a success in portraying an imperfect, greed-motivated person who thinks they are in the position they are in because they are the best, but actually aren't. Maybe that hits a little close to home for some.