If only designers had any say, this'd actually be true.
Design has barely been born on computing devices frankly. Apple was the first, and remains, the only computing company with any taste at all. So really, the entire industry has some designers working for one company, that the rest shamelessly copy.
Shrugs, as the old maxim has it "In matters of taste, there can be no disputes" - I'm not a massive fan of Apple UI's on the ipad (and my house owns three, two are mine for testing and one is the boys), they are serviceable enough but they put everyone in the same slot, if you happen to fit that, great but if not then not so great.
That said I'm not the target market and I accept that.
Design has barely been born on computing devices frankly. Apple was the first, and remains, the only computing company with any taste at all. So really, the entire industry has some designers working for one company, that the rest shamelessly copy.