You wanna talk about wasting time?
I spent probably an hour in total to dig up this cover. So yeah, I will not apologize for the 10 seconds you "wasted" reading my reply...
Have you ever heard the phrase "beggars can't be choosers"?
When you are asking people for stuff - especially without giving something in return - then yes, you ought to be thankfull for anything you get.
It is fine, if you are not satisfied with the result. But "that mature thing" would have been to be thankfull anyway and wait if someone else shows up with something better.
Don't pretend you responded the way you did out of concern for other peoples time.

If you are so concerned about this community, how about contributing something yourself for once? And if you feel people have been rude to you, that is because nobody likes leechers with an attitude.