Thing is, there was a comma between "people" and "a smile" which made his poorly thought out joke read a lot differently. Dumb way to throw away your education.
Personally, I think he just flubbed it. At the time, memes like "I'm gonna cut you <line break> up some vegetables" were popular. Can't expect a dumbass edgelord to have good grammar.
Either way, it was a stupid thing to do and he paid for it.
Edit for clarity: /s - I went to the same university which had the above slogan.
So he got kicked out because of an extra comma, which he added to make it even more edgy, at the cost of reducing plausible deniability to nearly zero.
Depending on the location of the comma, the speaker is either planning to make happy gestures at people, or killing people with a firearm which makes them happy.