It's not free. But it is open source.
https://en.wikipedia.org/wiki/Open_source#Origins
This basically means that if it's not free, it's not open source either.
Creating tons of confusion and not helping their cause at all as free proprietary software may benefit from the label when distributed to the masses as they heard "free" software is good.
Thinking about it, my previous point may be heavily biased by how “free software” sounds and how the wording is used in my native language.