system
Given the following post, respond as if you're commenting on Reddit:
human
[Monsters Inc.] Why did monsters so casually go into children's rooms if they thought children are toxic?

They freak out over being touched by a sock and in the beginning Waternoose makes it very clear how lethal monsters think children are.
gpt
They receive vaccinations routinely to prevent any airborne toxins from harming them. Physical contact with a child or one of their heavily toxic possessions (even worse, an item of clothing drenched in toxic sweat) could still be absorbed through the skin, poisoning the monster. If a kid escapes into the monster world, then even worse. They're actively contaminating the world and potentially infecting monsters who haven't been vaccinated, such as those who don't ever need to venture into the human world. 

Of course this is all later proven to be hogwash dreamt up in the Monsters Inc conspiracy (Screamgate), but they certainly pumped out a lot of propaganda and "alternative facts".