I didn't thought I would have faced this kind of problems when I released my plugin. You are the first and only one who provided this kind of feedback, I am very surprised...
Having said that, few points :
1/ The WordPress site said : "Your plugin must be GPL Compatible".
You can interpret this sentence in two ways. The first one is : "your plugin must be under GPL" and the second one is : "your plugin must be able to work together with GPL licensed S/W" which is the case for WordPress unless I am wrong so my understanding is that WordPress guys are just asking your plugin license to be compatible with WordPress license.
2/ What are compatible licenses? Extract from the GPL page :
What does it mean to say that two licenses are “compatible”?
"In order to combine two programs (or substantial parts of them) into a larger work, you need to have permission to use both programs in this way. If the two programs' licenses permit this, they are compatible. If there is no way to satisfy both licenses at once, they are incompatible..."
My plugin is in essence compatible with WordPress GPL license as I allow users to run it together with WordPress. If I wouldn't (by asking them to notify me for any installation or restricting the delivery), then I would agree that these are hardly compatibles.
But my plugin is available for free (no money), the source is easily browsable and the plugin can be downloaded easily.
I spent hundred of hours developping this plugin. You could understand that I'd like to protect a bit my work. If you don't, you probably have a good salary beside your wordpress plugin coding and that's not a big deal for you if your work is stolen as you don't expect anything from it anyway...
Now we could speculate on the risk. Everybody has its own vision on that.
To close on this discussion :
1/ Based on my current understanding of the GPL "compatibility" and the WordPress statment, my understanding is that my plugin with its license (and what you describe as restrictions) could stay here. Again, the gain here is more for the user than me.
2/ Many other plugins don't have any license or are more restrictive than mine and still they are on the repository.
3/ If my interpretation is wrong, then I would be happy to get the point of view from the WordPress repository admin so that we can see what can be done...
Having said that, I thank you for your time and wish you a good day!