Do you not agree that different people have different talents? Some are good at constructing clever arguments, some can compose beautiful music, and some can solve partial differential equations in their heads.
the IQ simply doesnt measure creative genius. if it was called "the test that measures how good a persons brain is at pattern recogniton", you wouldnt care. you'd simply state that you're not particularly interested in logical reasoning.
intelligence, in terms of IQ, is a more or less well defined metric. in popular language, its conflated with "not being a mouthbreather". thats why people get pissy when they dont score above average on an iq test. its kinda pointless, really. people only care about iq tests because of the name.
Intelligence is an ill-defined, nebulous quantity. IQ is a precisely defined quantity. Since intelligence is hard to measure and IQ is easy to measure, it's tempting to use one as a proxy for the other. But I, and the other posters above me, just don't find that very convincing.