Why would Hashicorp give the slightest worry to losing thousands and thousands of non-paying customers?
Because it goes hand in hand with losing hundreds of unpaid developers, testers, bug-reporters and evangelists.
If I wrote an open letter decrying Salesforce for not open sourcing their codebase, nobody would take me seriously. But we expect better from Hashicorp for some reason.
Because the community contributed to the codebase. Salesforce was never open source, Terraform was and took community contributions, that's the reason we have different expectations.
[Docker] can barely muster a viable business
Docker split their development and enterprise offerings into two companies years ago and
both are making money.