Read it, still don't see how it proves you're right. As a matter of fact, the same article shows exactly how to represent non-whole numbers in base two. Same principle as in base 10 or any other base, just with powers of two instead of 10. Nobody is extending anything. What we're discussing is a number system
Go read the entire first half of the Wikipedia article on it, and you'll see I'm right. There's nothing in binary that denotes a decimal point. That's an extension of binary. It's like saying your compiler supports extensions to let you use nested comments or something. That doesn't make it part of the core system, just because you extended it.