Nowhere in the license does it claim that it’s an Open Source™ license.
This is an incredibly misleading comparison. The subsequent clause is a complete contradiction, not a subtle clarification.
I am fine with licensing your code as you wish, but I will always oppose attempts to redefine the widely understood and established meaning of "open source" that has been in place for over 30 years. You don't get to change its definition.
Please don't embarrass yourself with your conspiracy theory nonsense. Besides that, Microsoft contributed to Open Source more than any other company.