https://www.fsf.org/blogs/rms/selling-exceptions
He's got mixed feelings, but says "I consider selling exceptions an acceptable thing for a company to do, and I will suggest it where appropriate as a way to get programs freed."
If of all people rms considers something acceptable, then whatever that thing is, it certainly can't be described as "virtually closed source".
If you release something as open source software, then it is open source software. The end. That's what the term means. Also licensing it under a proprietary license doesn't change that. Free software licensing is not "try before you buy", and it is not "free usage for non-profits". Open source and "not for profit" are not synonyms de facto or de jure. You can use GPL'd software in commercial products and in fact many people do, frequently. You probably have a dozen copies of Linux in your house in various appliances that you don't even know are there. There are many other examples.