He means that there's a critical mass of developers who will take one look at a syntax and move on if it doesn't have curly braces and semicolons. It's not that they're enamored with having a needlessly awkward syntax for function pointers, it's just that a syntax that isn't 95% of the way to Java just looks freaky weird to them, end of story.
I don't disagree that syntax matters, but C's is hardly a shining example. There's a network effect with programming languages, though (libraries, documentation, community, etc.), and there's a certain amount of realpolitik in designing with "C-Like Syntax" in mind.
I'm more worried about languages with ugly semantics. Odd syntax is only skin deep, but bad design goes straight to the bone.
