Of course, people can flatter other people's work without technical knowledge, that's absolutely acceptable.
We do that, always, especially in art. In music, for example, everyone likes or dislikes some piece of music or song and that is natural, nobody cares about the notes, music bars and so on. That's for the pros, sure.
For visual art it's the same, you like it or you don't like it. It is valid, that is the goal of art, to arouse feelings, but not for those of us who call ourselves "professionals".
An expert may or may not like some work, but can distinguish levels of quality independent of personal taste.