One of the main purposes of patents is (ostensibly) to allow innovators a temporary monopoly to recoup their R&D investment. From that perspective, a UI patent that isn't specific to applications in your niche seems like a bad idea. If I'm not competing directly with Tweetie, how are they harmed by my use of their UI technology? If they're not harmed by my use, why are they being protected?
Because their UI being innovative and one of a kind might well be a corner stone of their product marketing plan. You and I copy it, and they can't market, sell and recoup the expenses as planned. Though in this case I suspect this is one of a "valuation booster / acquisition facilitator" patents rather than anything else.
