Since you ignorantly closed the discussion without allowing for a response, especially that you ask a question, I have to open another issue to continue the discussion, that's very lazy by the way on your part and kind of pathetic, so either act like a serious developer or just leave and go play in your sandbox. (#1)
"I can't reproduce it on my end, see http://lesterchan.net/wordpress_dev/, I have choose Print Icon Only"
Well just because it works in your vacuum with hard-coding doesn't mean it works. I gave you the screenshot of the item, when its chosen, it disappears completely and only comes back if you go in and choose with text. Now just because it shows up in a test you have setup god knows when and how, doesn't mean it works and it doesn't truly reflect a real life situation. Can you go to any blog right now, not the dev one but a real one, and still prove that it shows up? Because I can prove that it doesn't.
"It is impossible to satisfy everybody. I don't see why modifying too much CSS is the plugin problem. So I will leave it at CSS for now."
No one asked you to satisfy everyone but in this particular case you actually can if you did your homework and were willing to do the work or knew how frankly. You can implement an actual interface to do it or leave it to be done manually, the user has both choices and that WOULD satisfy everyone. BTW, if you knew anything about maintaining a serious distribution you would know that modifying site/theme CSS to implement a plugin is bad practice as any update that comes in the future to that theme or ever possibly the core will replace those changes.
"I agree, but when I do this, the rest of the people will want to turn it off and place the code in themselves because they want to customize it rather than placing above or below the post content. Again, it is not possible to satisfy everybody. And I don't see why including it in a theme is not clean, it is the only alternative out there."
Again, you can provide the mechanism to use it or don't use it, you don't have to remove it, you have a very bad way of thinking all or nothing and for a programmer, that's a fatal mistake. We make things happen, not give up and concede. You seem to find it easier to just throw your hands up instead of do some work to make it better fit multiple scenarios.
"Where is the complain? http://wordpress.org/support/plugin/wp-print I didn't see anything about this. Just A FYI, I subscribed to my plugins support thread and I read it daily. If I didn't reply means user didn't bother to search or he asked a question that is not related to the plugin."
They are there if you actually bothered to read and I doubt you don't answer because the questions are invalid, because at the very least you can post the link to what they need to read without saying anything but you say nothing. Trust me as someone who supports over 24 support sites that comprise top 5% of the world's support communities, you are just lazy. Good support means engaging with your community, even if they ask a rookie question, you can point them to the answer, especially that your support material is scattered, disorganized and not very complete. You just posted comments here and there hoping everyone will jump through the hoops and wander around looking through your bragging to get to two sentences that might be helpful or in most cases not.
"I am still maintaining it, but I doubt I will add in any features unless it is from others who submitted a pull request to the plugin."
Well it should be made easier for you soon as you will become obsolete. I was hoping to implement something to save time but after wasting this much of it having a discussion with someone clearly clueless as you and trying to educate you on proper support, I decided to save my time and just build a better solution that integrates perfectly with WP from scratch and after I finished, I submitted it to the WP team for integration into the next version at which time people won't need your half baked tool, they will have a fully featured one built in and they can just ditch your ass. So enjoy the ride while you have a ride.