It's helping people who want to help, or learn how to help, themselves that appeals to conservatives.
One's attitude to volunteering is often a good indicator of one's voting preference. Democrats I have known (LOL) hate the idea on idealogical grounds because "the volunteer is taking away the (dues-paying, placard-waving) union member's job.
In Vancouver, for example, parents were forbidden from helping in schools.
President Bush is trying to raise awareness of what values improve a society to a populace who have spent far too much time "watching day-time TV," (his phrase) It IS the Thousand Points of Light of his father - obviously a Bush family value.