This is not correct (or, is misstating the reality). They're discontinuing their product because Twitter banned their API keys/developer account and no longer supports third party clients through their API. There is no longer a supported API for Twitterific to use.
Unsure if you're familiar with what happened over the past week, but twitter revoked their access without any announcement or communications. Openly hostile towards developers using the API.
To continue developing and supporting Twitterific would be to fight against someone/a company who does not want them.
like I said, all your words taken together need to make sense, or they are open to reinterpretation and critique. This is the autistic way of sentence analysis.
I don't agree with the unannounced disconnection of the API, as there was room for compromise, such as third party clients only available to people who pay the subscription to Twitter, but alas, the new corporate direction is that they want the ads to go through, and that wasn't happening at all with the third party clients.