I simply made the argument that those with children tend to have longer time horizons when making decisions and that longer time horizons lead to better decision making. Even if this is true, using a statistical tendency to disenfranchise millions of people is still silly. By that reasoning, men should be taxed more because they commit more crimes.
We use statistical tendencies to disenfranchise felons. There are million of felons, many of whom are productive members of society. We use statistical tendencies to disenfranchise those under 18. Many high school kids are better informed than adults. This doesn't seem to be fair.
Society makes decisions based on statistical tendencies all of the time.