Just read both this thread and the one in the Apps forum. This thread has a distinctively more negative tone, especially with a ton of people sneering down on the "complainers," calling names like cheapskates and idiots-who-bought-nanoBundle2-just-for-Tweetie.
I believe Warbrain's post summarized the issue the best:
Because the real concern is that people bought MacHeist because of Tweetie 2 and now they won't get it. I don't think people are all that concerned about the iPhone side of things outside of Twitter gobbling things up like another company we all love.
Since Atebits has announced that the beta for Tweetie 2 for Mac is coming, the concern now is about what will happen to it after the fact, such as continued development (new features? bug fixes?). Or will it become neglectware as someone else has said. This is something we can't assume and is essentially up to Twitter to decide. (For anyone who doesn't know, Tweetie for Mac belongs to Twitter, confirmed on the Twitter Development Talk Google Group.)
No one is saying that Tweetie *isn't* one of the best Twitter apps for iPhone and Mac, and of course many people are glad for Atebits since this is a huge break for an indie developer. But a lot of the time customers purchase indie apps early in its development cycle based on the potential they see and so they pay to support its continued development. In this case, many people, knowing that Atebits can deliver quality apps, bought the bundle for an exclusive beta and its potential (some in part, some solely because of).
Personally I was on the fence about nanoBundle2 until Tweetie (and the promised beta for 2.0) was added, the only other app I use regularly is Flow. Does MacHeist give great deals? Yes. Is giving to charity a great cause? Yes. But even so, people buy bundles for different reasons.
Sorry for the long post.