Greedy? Why would you bet your product and customers on another company? If someday Hashicorp suddenly died so that nobody adds new features or fixes bugs, you can't do anything about it because their code isn't "open source" even though available, when a "true" open source project is just next door. Any big enough company will think about what is the safest approach to their product.
(Of course, companies do go out of business, and products stop to be maintained, and the example here is a bit extreme, but the point is that company will do what makes the most business sense)
It is not Oracle who are using terraform, it is their customers. Terraform is the underline tech that powers the tooling suit that the customers use to manage their oracle cloud.
It makes perfect sense for them to push their customers to move to the more permissive licensing to avoid any legal issues.
Only when it isn't legal issues that dump money into Oracle. They absolutely love and adore pushing their customers to less permissive licensing which can encounter legal issues when they are the ones benefiting
They seem to think that just because a company makes non-open-source software, it shouldn't itself prefer to use open-source rather than proprietary software?! That makes no sense, of course. Specially considering the non-OSS is now owned by IBM which directly competes with Oracle on multiple fronts.
It seems to me that OpenTofu is actually backed by many companies in a similar position to Oracle, which don't want to have to rely on IBM for things they have tight integrations with.
(Of course, companies do go out of business, and products stop to be maintained, and the example here is a bit extreme, but the point is that company will do what makes the most business sense)