The question “Why do I need 50 reputation to comment?” was raised many times (see duplicates of Why do I need 50 reputation to comment? What can I do instead? ).
It will be useful on Comment Everywhere Privilege page ( and corresponding pages on other sites) add a reference to Why do I need 50 reputation to comment? What can I do instead?, e.g.
However, commenting on other people's posts is a privilege gained from earning reputation (The reason why is described here).If you haven't earned it yet, try to get comfortable writing answers first.
