I find it hard to believe that any serious person would argue that "code that is open to the community" ≠ "open source code".
I think it's realistic to assume that the developers who wrote the README, and the lawyers who wrote the license didn't talk to each other much when making decisions about how much freedom users were going to have with the code.
They've worded it just as they intended imho (ignoring the confusion over fork aspect) as it's how to ensure that they're still in charge & to prevent anything derivative as they really don't like that based on prior experience with them.
It's also mostly about getting that lovely free dev work because with oh so many capable devs out there they're just going to be clamouring to want to give up anything where possible to be able to work on this along with trying to appear to be doing good. Even though they've halted development at least 3 times I'm aware off & ditched a number of dev teams under their 11yr tenure of ownership.
I share the same feelings, and I think that the way they phrased it is intentional. They are clearly capitalizing on the goodwill that is built around open source software over the years. In a "having the cake, and eating it too" kind of way.
>its source code was opened to the community
I find it hard to believe that any serious person would argue that "code that is open to the community" ≠ "open source code".
I think it's realistic to assume that the developers who wrote the README, and the lawyers who wrote the license didn't talk to each other much when making decisions about how much freedom users were going to have with the code.