Why rounding odd font sizes to even?

Today I started implementing a design that had some copy text with font size 17px. My fellow web developer told me that we should round that to 18px. He thought that the text may look better. He was not sure of it. He said that he at his former job was told to round all odd font sizes up to even.

So my question is: do text with even font size look better than odd? Or what is the reason to round odd font sizes as given by design to even in the css?