Catering implies servicing, or a subserving one's own opinion to the whims of others. Which means yielding your own personal desires to the desires of others - which also means conform. I'm quite aware that the way he was using contour was synonymous with conform. However, the message he was trying to convey was better served with cater and the recognizable idiom.
If one alters an idiom, it generally makes the speaker look like they don't have a grasp on what they are saying - in speech, altered idoms work far better than in text because there are cues in the tone. Again, idioms are not cliches - just as regional differences in the name of things are not cliches. It's about the figurative meaning that's known because of it's usage - looking at the literal meaning does not always convey the full meaning in idiomatic expression. Something like "spend time" or "act of God," can't be altered without changing the meaning attempting to be expressed. This isn't a restraint on language, it's simply the way idomatic expressions work.
I believe that the English language can be subtle, and it does have the potential for variety. However, I don't think we're going to agree on this, as I can see you disagreeing with my points on the ability for others to understand altered idiom. I'd hate to drag the name ops board off topic with a long debate on the usage of expression and word choice in language. Agree to disagree?