I'm currently doing something similar to this as the natural progression of the method I described here. The main difference is that instead of maximizing points, I'm holding myself to a budget of points.

It started by me telling myself I was going to spend two hundred fifty minutes / day doing useful self-improvement type activities. Then I decided that certain activities were only marginally useful, and started counting them at a rate of one minute per two minutes, and others were extremely useful, and counting them at a rate of two minutes per minute, and now it's more or less the same as your point system. I also subtract points for certain things I want to do less of. I've been doing it for about a month now pretty successfully.

At some point I want to make a post on it, but not until I've got more to say about it. I'm trying to think of it with an economic metaphor, as the personal equivalent of subsidizing useful activities and taxing useless activities to change the resources devoted to each, but I can't really present the analogy coherently until I understand the mind better.