I used to laugh and make fun of any and all signature quotes. My original quote was "No, magic is NOT dead." I used this because at the time there were a lot of Kevin Chen types out there proclaiming the death of magic and how it's dead so they're getting out now while the going is good.
Now, my quote reflects how I feel about those who never step outside of their "comfort zone". You know the type, the ones that NEVER play any other deck than the latest Broken.dec or commits to only tournament play because otherwise, it's useless to play casually (they think "What's the point?").
I too, don't really read extremely long quotes, but that doesn't mean that they're not important or haVE A UNIQUE MEANING (damn caps lock). IMHO, if you can't portrait your signature quote in one small paragraph, then you should maybe think of another angle.