It's worth pointing out that even individuals can disagree with themselves over the correct course of action in civic affairs. The debt ceiling debate is a perfect example: I hate paying taxes, but I also want the government to restore cuts to education, transportation, and other things that private industry isn't good at providing.
Some of these politicians truly have no idea and without feedback from the voters in the form of letters they'll just do whatever they're told by their senior party members.
A phone that doesn't ring off the hook, an email box that isn't full to overflowing, and a batch of mail that fits on your desk doesn't convince anyone to do anything.
I swear some of these politicians would vote to ship a hundred billion dollars in cash to the moon if they thought it would score them points with voters.
However, -even if- you had completely rational and competent politicians (Canadian, but really the same apply to us as well), the 'politics' we see is a meta-game run on top of the actual system of running a country. Sometimes the meta-game and the actual system happen to align, and everything works out more or less ok. Other times, they're retardedly out of whack, resulting in tears and frustrations for all. And due to how incentives are set up, any rational politician will play that meta-game (less they not get elected, and loose further opportunity to affect change).
The purpose of letter writing is to attempt to temporarily re-align the rules of the meta-game. The author's idea of a website just to vote on a plan is at its very essence trying to achieve the same goal, to realign interests and rules. But it runs into the fact that your government (and our government) doesn't work that way. There is no system or precedence in place for a citizen direct vote 'default' law. Especially with such short notice.
In other words, its the same type of wishful thinking that drives developers/engineers nuts when 'dumb marketers' just assume that computers can do X Y and Z while making your ice cream and watching your kids.
https://plus.google.com/111597209120074513359/posts/b6zXcbT7...