Actually there are relatively few real (TM) open source projects driven by the community, at least if you look at important projects. Many open source projects are just commercial projects driven mainly by a single company. Look for example at Redis, MongoDB, MySQL, and Elasticsearch. They follow exactly the model described in the article. Technologies like these could have been developed by a community, too, but it…
Postgres (do we really still need the "QL" reminder?) has demonstrated staying power, and repays invested time in spades. Linux, obvs. Rust, it's still too early to be sure about. Learning it will be at least educational, maybe formative, and at worst it won't be taken away.