TextMate lacked polish, I think that is the fairest indictment you can make of it. It really did bring some awesome features and customizability to the table with probably the lowest difficulty-of-customization to flexibility ratio in the history of editors. It's easy to dismiss how impressive it was in 2004 because so much of it has trickled down to other editors. It really goes hand-in-hand with Rails which people are so quick to criticize today because of how much improvement it spurred in the competition.