I consider myself a connoisseur of cinema. I intend to pursue a career in film and television (albeit more on the writing side of things), but I have still studied many of the important aspects of framing and composition. And let me tell you: this show gets it right. On top of that, it's cleverly written and genuinely entertaining on many levels.
What I think may be the most important factor is that I'm outside the target fanbase. Nothing destroys a show faster than trying to please its fans. So since it's not trying to do that, the bronies can look forward to many seasons of pleasure.
Interestingly, I'm currently engaged in a debate with a friend who refuses to watch it yet continues to criticize it based entirely on speculation. In the length of time we've been having this rather one-sided debate (I say one-sided as he has yet to provide a piece of logically-cogent information), three more friends of mine have started watching it and enjoyed it.
You can see some more of my thoughts here: My Deviant Art page