It's an episode that ignores the impact actions have on people and the reality of the situation the Enterprise is in. It's an episode that systemic to every. Single. Problem with Voyager. It's no surprise the episode was solely written by Brannon Braga the kind of "it doesn't matter after 45 minutes episodic television."
Consider that the Enterprise has on it over 1000 persons a number of whom are civilians and children. ALL of these people were "de-evolved." You can't have something like this happen without considering the *real* impact it'd have on people and lives.
Beverly was sprayed with a paralytic venom that necessitates reconstructive surgery on her face.
Worf, and presumably Riker, both KILLED PEOPLE in their altered forms.
Riker's brain was made "much smaller" by this infection and presumably this goes for everyone else. This means parts of the brain were MISSING. Parts of the brain that contain memories, learnings and experience.
Individuals do not evolve, species do. Over the course of EONS.
This was all kicked off by an absent-minded hypospray shot from Beverly.
All of this happens, people are killed, brains are destroyed, faces are destroyed and all of this happens over the course of a couple of days.
At the end? Everyone shrugs, laughs a bit at Barclay's insecurities and life goes on as if something very damn serious hadn't just happened.
Fuck-you Brannon Braga.