Many of us interpret criticism as an attack on our own value, taking criticism personally when it is not.
It could be an attack at times because a guy once called me "stupid and foolish" for taking offence at why I disliked Bitcoin. It's disliked, not even dislike. I guess some are overbearing and attack/disrespect people at will which is not good.
Was it me? LOL!
Well, if that is all the guy told you, then I wouldn't even consider it a criticism, but just plain ad hominem since he is incapable of arguing effectively. But, if it is accompanied by valid arguments, then you can accept it as the way he is expressing himself. For example, some people are more vocal in their feelings while others are more intellectual and restrained. Don't take away the other's right to express themselves in a way they feel comfortable with. The language we use to express ourselves (or our attitudes) is often a reflection of our personality and character. You don't have to be a wimp about it.