My takeaway is that (ignoring holidays) negative events make Twitter more unhappy than positive events make it happy. Yet another reason I'm not on Twitter!
I like that. What's the actual quote?
Edit: it's probably this:
> …the computer is the most remarkable tool that we’ve ever come up with. It’s the equivalent of a bicycle for our minds.
Mentioning negative events therefore seems to directly decrease the happiness score, so a conclusion like yours is almost tautological -- when a negative event happens, people talk about it, so the algorithm infers that people are unhappy.
What's more, it's misguiding to say that people talk about things that happen. People talk about some of the things that happen. Media plays a big role in the selection. People also tend to adopt framings. Which is to say that people's happiness does depend on what's being talked about, if we agree that happiness is the positivity of thoughts held.