It appears to me that the point being missed is on that screen over there.
"Users choose to communicate via Twitter"
You gave them that choice by signing up for an account and making information available in that fashion. If it weren't an option, users wouldn't use it. They would use a method you had chosen to implement- say, an email address or online form. Saying that they use it because they wouldn't have bothered otherwise is a speculative at best conclusion.
"Users who chose not to subscribe to RSS," which is less hassle than Twitter- which they have to have an account for, which has less room to fully communicate information... again, this is a choice as easily offered as Twitter. What if you offered them an RSS feed of just software updates... you do know that RSS doesn't need to just be for blogs? It's any well formatted XML doc which complies with the RSS spec- a node could be the entire list of code changes, bugs fixed and a link to get it.
And finally, the point is that the communication on Twitter is not as good as other better free, open and incredibly more widely used than Twitter options. Your users and your software are being shortchanged by the medium. Or maybe this goes to my point of them not really caring about it if they deal with it via Twitter?
BTW- sourceforge is a fantastic resource for keeping up to date those who are interested in your software.
I do like that the only commenting on this has been in defense of Twitter, which is still a big who cares in my book, and not much at all about the disease of internet advertising.