There is a case to be made they took it to an extreme, but there is too much going in the other direction as well. It's not like most teams are working on the meat of the product anyway - they probably spend 40% of their time running a small project on Kubernetes and getting rid of daily security warnings from NPM.

Somehow they managed to become one of the most important websites for software developers despite neglecting every product feature you miss.

They have never made a dollar of profit in their 15 years of operation and just sold themselves to a private equity firm for pennies. "Most important website for software developers" doesn't really mean anything unless one can also be a sustainable company in the process.

Was it because of "neglecting every other product feature that end users actually want"?

Failure to monetize is usually the exact opposite of failure to please users.

Have you seen their code base? They did not over optimize the DB engineering by any means that I could tell.

Having a simple monolithic database is not optimizing your DB engineering by any means.

edit: and inventing a better ORM doesn't count either.