Matrix is developed by a for profit entity, a group of venture capitalists and having a spec doesn’t mean everything. The way Matrix is designed is to force into jumping through hoops and kind of draw all attention to Matrix itself instead of the end result
For all the people about to downvote:
Decentralized communication protocol Matrix shifts to less-permissive AGPL open source license Element, the company and core developer behind the decentralized communication protocol known as Matrix, has announced a notable license change that will make the open source project just that little bit less appealing for companies looking to build on top of it.