Syntax is supposed to be a win. It's supposed to be convenient, readable, shorter.
But Lisp -- the language where you write your code in trees without syntax -- is known for being very succinct.
So I see two possibilities:
1) Most syntax isn't actually a great idea
2) Other languages are so handicapped by lacking features found in Lisp that it more than makes up for syntax advantages (and libraries, and all Lisp's other deficiencies)
I'm leaning towards (2), but I suspect a fair amount of syntax is not helpful and some is bad.