Hmmm... I don't know about that. There's a reason my opinions on films are not humble. Knowledge of cinema history as a critic does mean you can make better comparative analysis and provide better recommendations.

For instance, someone once raved to me about the film Extreme Measures, a 1996 medical conspiracy thriller starring Gene Hackman and Hugh Grant, and asked if I'd seen it. Obviously, I had (having seen it during the original cinema run). I don't hold that film in particularly high esteem, and pointed out it is similarly plotted to the vastly superior Coma from 1978, and sent the person in question to view that film as well. They came back saying it was indeed far better and that they wished they'd seen that one first.

Obviously, all opinions on film are subjective, but some are a lot better informed than others. As for director's opinions, I have more sympathy with you on that front, as sometimes directors have particular genres they don't care for (Ken Loach's laughable opinions about Star Wars, for instance - which he dismisses without even having seen).