In the signup process, Twitter asks for your e-mail address and password, so they can check your contact list for any friends that also use their service. I just couldn't do it. Even with their promises that it wouldn't be abused, I'd have to change my Gmail password anyway.
As a self-aggrandizing aside, that's easy enough to do. I only know a few of my passwords by heart (Windows login, Lotus Notes, Keepass), and the rest are random keyboard mashings of letters, numbers, and other characters generated and stored by Keepass. So changing any password is fairly painless. It's just the thought of giving away that information that has me all cautious-like.
Now if I don't trust them to get through the opening steps, and I'm not really into the whole Twitter revolution, and I am really through with the work-related task I needed it for, why keep it, right?
What?? Why would they present this as an option just to tell me "no"? That's frustrating enough. And I'm no expert on Twitter's network structure, but as a typical frustrated end-user wanting to get out, I can't help but think: Wouldn't the absence of an account help alleviate some of the chaos? Maybe their network isn't coded well. Maybe I'm not really "deleting" anything. Or maybe the error message is lying. No matter what reasons I come up with, I just want out more. =(