Many syntax highlight themes seem to hide comments in code by decreasing their contrast. I'm strongly against that so for me the author lost credibility when I saw that's more or less only what his theme do.
Never question someone's credibility because their preference differs from yours. It'll make people question your credibility.
Of course, legible code is more important in most cases.
One could make the opposite argument that comments are the important part and you only need to read code when diving in. This would be sort of a literate coding. I'm torn between making comments dimmer or brighter.