You don’t have to. I am not forcing anyone to go and use it. But it is weird how people go out of their way to post just a random rant on a community for people who want to give and receive feedback.
If the comment was about criticizing something specific about the site (“It looks ugly”, “It didn’t work”, “why are you using login with third-parties”, “some other tool already does it better”, etc) I’d have no problem with it. But I really, really don’t see the point of going around just putting down other people’s efforts while going off merely by their own assumptions and biases.
I find that hard to believe when I see his username on the list of downvoters.
And even if you shared that opinion, wouldn’t you be at least interested in alternative methods for job searching?