Earlier quoted context omitted.
I think, paying attention to the comments here, you should consider that your communication is an issue. The whole license in general, the need for it, the "it feels OSS, but its not" ... the artificial license limit... lots of red flags, and a lack of clarity.
The person who said the thing about OSS corrected himself (I assume it's a he) and admitted he just hadn't read the page properly. I just explained why the limit isn't artificial. But you're right, I'm sure my communication can improve. I've been spending a lot of time on this project so am somewhat "blind" to mistakes. All I can do is listen to the feedback here and improve.
I think the combo of the nag screen and the inability to pay to get rid of it is a big part of the problem. If you're not going to let people buy the software, you shouldn't add a penalty/hurdle/annoyance to their usage.