Look at Elastic's product, i.e. Elasticsearch, Logstash, Kibana, etc. Or Oracle with MySQL and Java. Redhat's OpenStack. Spring for Java. EhCache. Even .NET from Microsoft is also starting to accept third-party work. There are a lot of such examples, and that's usually a good thing. Because it means that there is someone with a different interest, than just working on cool things, behind the product (i.e. Money) and driving it foreward. Also, having professional support offered makes it sometimes much easier when convincing stakeholders to build upon an OSS product instead of a closed source equivalent.