Making people copy & paste is an 90's mindset. If you think too much noise is being published, ask the author or stop following him. Or make add him/her to a list so you can watch his/she's messages without RTs.
I want to know news, and I want them FAST. Twitter does an amazing job on this field, because when something is really important a lot of people are gonna share it. RTs are also is very important for Trending Topics!
imho not wanting RTs on Twitter is not fully understanding Twitter.