Like any artform - once it exists in a medium where an outsider can see it, the outsider's opinion isn't inherently invalid for for not being 'official'™. There can and will be personal biases in any interpretation. This is expected. By sharing discourse amongst critics, there is great transformative power with facets like social commentary and marginalised groups finding a source of representation.
We have death of the author. We have subtext in everything that can possibly be the subject of analysis. We even have dorks who will try to rule 34 and/or ship every character in their own fanfiction.