I don't think this dismissal is quite fair, especially regarding this work being unscientific or having negative value to humanity!

The paper described here isn't survey-based; it actually seems very quantitative compared to other psych papers (they collected audio for "150,000 recordings" and computationally analyzed the data; the survey part sounds more like diary data collection). But even if this was entirely survey-based, it wouldn't necessarily be useless.

I do think that it would be better to cover trends in the literature instead of individual studies, but in this case it seems the paper has important implications for sentiment analysis and computational social science in general. I currently hope conferences don't go away!

I agree with your sentiment. These types of studies would be fine for discussion amongst people in the field. The problem is the headline is the only thing that will make it to social media and some people will take it seriously.

My own opinion has always been that the majority of people who are happy are too busy doing what makes them happy and not posting it on social media. Yes, they are those who are happy and have time/capacity to genuinely post on social media but I must admit to being a sceptic to most posts purporting constant happiness. Maybe it's just me but we all have ups and downs and that is life.

This is fundamentally a descriptive statistics question (how do X and Y go together) rather than a causal inference question. Descriptive claims still have value; it is clear that both self-assessed happiness and use of language have omitted causes not explored in this research. If anything, this is mostly useful as an exercise to critique operationalization of emotion as sentiment scores in NLP.