What is it about photographers looking at the work of others, that makes them think that they need to critique a photograph even when it isn't asked for?

We've closed our studio, and used a previous photo as an example of a background that is for sale, in an ad.. Someone actually critiqued it. A for sale ad.

Does it make you feel better about yourself, or like you know more than someone else? Do you think that your opinion is just that important? Or did you buy your masters certificate with your entry level camera?

Why do people feel the need to do this?

Am I just having a bad day?