Comment 2 for bug 852414

The other problem is that copying the original user's name means that you lose some of the 140 characters. It's not uncommon to see users with Twitter names of 10+ characters, so once you include the ♺, a space and the user's name you've lost 10% of the available space, which often means that a retweet won't fit without editing (which sort of goes against the point of retweeting).