I don't think of using FB as a memorial as necessarily bad or good; the truth it's somewhere in between and varies by individual. The problem for FB stems from the fact that it was never designed for this behavior. A vast majority of deaths on FB are never reported, and those profiles stay in the viral loop. Those that are reported put FB in the awkward position of being referee of the deceased's identity.
Ultimately, I was dissatisfied with allowing FB determine how we, as friends and family, were going to remember my friend's life. I don't like that his jokey profile photo is now stuck there forever. I think we can do better. But beyond FB, the reason I'm excited about building a platform for memories is that the Internet in general does a bad job speaking in the past tense. We are focused on providing tools to help people tell and preserve the stories of their loved one's lives.