Basecamp made a questionable policy change, then the CEO started mass blocking everyone who said anything remotely critical of him no matter how kindly and politely they said it, then a third of the company took severance package offers. Paraphrasing one of the viral jokes: they hate when people take 30% from them, so it looks like they stepped back to rethink their actions.
DHH is the CTO, not the CEO. And, like you, most of the Twitter mob had no idea what Basecamp was before starting to call him Nazi, white supremacist, racist, etc.
Someone (you?) blocked on Twitter is inconsequential and not relevant.
tl;dr: Basecamp decided to ban political/societal talk not related to work on its web internal group chat. Some people where outraged. 18 of their 56 employees resigned. This post is the aftermath of all of that.
