Ultimately, I believe what people miss in this show is the message of "Sometimes, now matter how hard you try, you still fail". There tends to be a focus on characters when it comes to this series, not that that's a bad thing, but it seems like most people haven't really thought about it that much. The message that there will ALWAYS be someone better than you at something I believe is a very important message to get into your head as soon as possible, and that, in general, life tends to be unfair. However in the end it shows that all you need is something to always work towards as best as you can.
Back on the characters thing, some may see all of them as somewhat simple and with little development. While I personally like the characters for what they are, I can see the obvious simplicity. Overall I think it's the messages that carry this show, the themes themselves are most certainly different than the usual optimism anime generally has. It's pretty good in my opinion, I would recommend this to anyone who is interested.
