I can't say I'm familiar with the other companies/their tools but I assume they're all somewhat nebulous to terraform - did they not try to contribute back to hashicorp terraform?

In the TF scenario specifically it seems like it would have been smarter for hashicorp to open the core oss project to some outside contributors more directly (potentially moving to a different "ownership" on GH).

Maybe they'll relent and throw support behind the new project. Who knows.