That is extraordinarily wrong.
Syntax:
1) affects the structure of a program,
2) affects how we think about it,
3) affects what is easy to do and what is not,
4) adds or removes mental strain on reasoning about the program,
5) forbids or enables certain kinds of errors.
And much more.
The idea that syntax doesn't matter and is "a matter of preference" is completely bogus. The human mind has certain limitations and capabilities. Some syntaxes cater to that, some do not.
No one using Brainfuck will never be as productive as Python, to take an extreme case.