I no longer have my S2 or S1, but I will answer. (I have an Ipod touch and owned an Iphone) The UI is amazing but not really what I wanted in a phone. The BB on the other hand was everything I wanted but had the fugliest UI. What is wrong about using a lock app that makes your phone look better or a theme that helps cover up the ugly UI?
It's like having a girlfriend that has mad booty and no breasts. Would getting her a boob job make you a boob fan boy? Would you dump her and go for a girl with boobs and no back? Food for thought. Why not have them both?
Although I havent attempted to iPimp my Storm 2... I can see why some would.
and the answer is simple, I love the look of the iPhone UI more so than the Storm 2, but I like the functionality of the Blackberry more so than the iPhone.