isn't the point of tv to entertain? if the science isn't comletly accurate who cares?
Things should at least make sense, be consistent and, well, not fall apart when thought about for more than a moment. I mean what if in an episode Picard just snapped his fingers, grew wings, and then started riding a magical pony through the galaxy. Hey, who cares as long as it entertains!
Being entertaining isn't a blank-check to do whatever the hell you want. You have to at least have it make sense and, ideally, an impact.
I'll accept a "virus" or other infection that can "de-evolve" people (or I guess more accurately mutate people into animals by scrambling DNA.) But it becomes harder and harder to accept it when you forget such an idea has consequences.
Which is this episode's biggest problem. It completely ignores the consequences this thing would have. Like I said up-thread there are civilians and children on the ship. De-evolved too. This de-evolution reduced the sizes of people's brains. Stuff you just don't "get back."
But the biggest thing is the humor moment at the end of episode that completely shrugs away everything that happened. Beverly's reconstructive surgery, Worf and Riker killing people, that people ARE dead. That this incident must have had some impact on the children and civilians on the ship but, no, we just have a funny little laugh and forget about all of that.