Don't kid yourself that it's anyone's hobby. If it were, they wouldn't constantly ask VCs for money, wouldn't run ads, and wouldn't have quarterly earnings calls about how they can grow revenue.
Twitter is just a less successful Facebook.
I don't think the world would be worse off if Twitter or even the concept of microblogging had never taken off.
But, with a general audience of hundreds of millions of users, it does devolve into smug, uninteresting arguments very quickly.
Just out of curiosity, when did you first come across Reddit? Prior to the Digg exodus 10 years ago it was a super solid community, and if my memory serves correct, it didn't really start going downhill until somewhere between 2012 and 2014.
Twitter is like a BDFL hobby project. I obviously don't mean that literally and am aware it's a publicly traded corporation. Twitter is a hobby project in the way that Oculus is a hobby project of Zuckerberg, even though Zuckerberg is the biggest shareholder of Facebook. It's a matter of where the leader made his money--Zuckerberg made his money from selling ads on FB (not VR), Jack made his money from selling a financial product (not social media).
Yes. it's brilliant and highly tasteful IMHO. I haven't responded to any of those myself, but their frequency is low enough and interesting enough that they don't bother me. I'm glad the site gets support to cover costs.
The best internet communities are ones that don't need to be a "company".
HN is a great example. HN is run by a rich guy as a hobby. There will never be ads, there will never be a board of directors, the UI will basically never change, there will never be consultants hired to figure out how to make money off of us posting. Yeah you probably could put ads on HN or data mine and make some money, but it won't be enough money for Paul Graham to get out of bed for.
Twitter is also like this. Jack makes his real money from Square. He can run Twitter like his hobby. That's what makes it so great.