Ok, thank you for explanation, but I on purpose came up with alternative explanation making a joke.

That’s because he killed death with pills, apparently, and now he became death himself, as it can be noticed by black clothes in last panel. And it is hard and ungrateful work to be a death. Why would he be happy?

Yes, it means layperson, but with derogatory cense. It is like using the n-word to describe black people (though not as extreme). If you mean average user, just say average user, unless you really mean to use derogatory term, that is.

But it’s less cruel to students.