They do NOT want an autonomous Ada community to pop up, they just want to attract programmers they can contract. Since they're basically the only noteworthy contributors for Ada, they're impossible to bypass, hence using Ada means submitting to Adacore's whims.
Ada is indeed a very well designed language, and with some recent language revisions, so have you ever wondered why it did not get any traction at all? Well, that's why.
Every 6 months or so on HN or Reddit, someone rediscovers Ada, gets psyched and tells everyone ... and then discovers the licensing / controlled ecosystem issues, and walks away. And we don't hear about it. For about 6 months.