People want to be given everything for free, to be able to put the absolute least amount of effort into the code they write, in the name of “open source.”

True! Open source = free stuff for a lot of people. This is why corporations like Microsoft encourage open source - so they can profit off of other programmer's hard work, without giving anything in return in most cases, and in rare cases giving a small donation. So, it goes both ways.

But open source nevertheless contributes to the commons when done well.

Compare and contrast: Free software.

I would be fine with it if Microsoft didn't constantly prattle about how VSCode is "open source" all the time without mentioning all those gotchas.