The Free Software Definition mentions "user" 22 times and "freedom" 79 times, whereas the Open Source Definition has zero occurrences of these terms. It doesn't seem surprising that the user freedom message isn't getting through if you completely scrub it from the messaging.
While what we know now is that Free came first and indeed Open Source was a different "offering" with a different focus, a response to it...
... I must admit I have heard and actually started to love Open Source several years before even hearing of Free Software
"I noticed this because I had the good fortune in the 1970's to be part of a community of programmers who shared software. Now, this community could trace its ancestry essentially back to the beginning of computing."
[...]
"And then I heard that somebody at Carnegie Mellon University had a copy of that software [for the broken printer]. So I was visiting there later, so I went to his office and I said, "Hi, I'm from MIT. Could I have a copy of the printer source code?" And he said "No, I promised not to give you a copy." [Laughter] I was stunned. I was so -- I was angry, and I had no idea how I could do justice to it. All I could think of was to turn around on my heel and walk out of his room. Maybe I slammed the door. [Laughter] And I thought about it later on, because I realized that I was seeing not just an isolated jerk, but a social phenomenon that was important and affected a lot of people."