Well in defense of this snarky comment, I have to say that the social sharing part of personal data like this can come across in this way (doesn't make it narcissism but still...).
The thing I like about personal data collection and cool new apis is what it could do for the individual, i.e. offer new insight, movitivation, encourage better behaviours.
But I hate the sharing part because it opens the door to over-sharing. Not just in terms of corporations having all kinds of data and using it in their interests, but also just simply the noise that gets added by people sharing information that frankly, has very little relevance.
I don't really care if someone just completed a 2 mile run and I certainly don't go to twitter to read automatically generated tweets about it.
1. Excessive or erotic interest in oneself and one's physical appearance
2. Extreme selfishness, with a grandiose view of one's own talents and a craving for admiration
So explain to me; what does quantified self have to do with narcissism?