The problem is when the readme file (or other marketing speak) says open source, so people think it's something that gives them the rights that OSI approved lic

The problem is when the readme file (or other marketing speak) says open source, so people think it's something that gives them the rights that OSI approved licences give, and then the license file says something else. For example, MongoDb's SSPL v1 or licenses with the commons clause. People are free to use whatever license they want. They should own up to it though instead of trying to paint their license as something else.