Because you can't just say "we're going to disrupt the way people campaign/vote/get elected." It is a staggeringly massive government bureaucracy even at the most local levels, and it prevents that kind of change at every point possible.
Edit: Not to mention the fact that as much as we like to pretend all politicians and millionaire slime balls, they're working people providing for their families. Very few are going to entertain the idea of running their campaign in an entirely different way because chances are they'll lose their job if they do.
I've worked on campaigns professionally from 2002-2010 and I've run local and state races, including my own for borough council and school board.
Why can't we change the way campaigns are run?
Campaigns would be the easy part to change, but even then it depends what you want to change. Are you talking about new technology? The Romney campaign is doing a decent job of utilizing technology in how they're collecting voter contact results from phones and doors, organizing volunteers and managing fundraisers. Obama did an excellent job as well in 2008, especially compared to the CF that was the McCain campaign.
If you want to make changes to the way fundraising works and the influence of money in politics, it will need to be incremental. That isn't something you can just cut off overnight for several reasons, the two biggest being that (A) nothing happens overnight in Congress, and (B) Members of Congress would essentially be shutting down their means of securing re-election.
Why can't we change the way people vote?
For the same reason a PA court placed an injunction on that state's Voter ID law: you can't deprive an otherwise qualified individual of his or her constitutional right to vote.
You want to have internet voting? You better have a plan to give everyone in the country high speed internet access and be prepared for the unrelenting torrent of lawsuits when the server goes down.
I'd personally like to see internet voting someday, but you really need to have massive redundancy systems in place and plenty of checks to prevent fraud. What happens if the server is down all day? What about peak traffic? What if the database gets wiped 30 minutes before the end of voting? Anyone who knows about how government contracts are structured knows that would be an IBM and/or Diebold contract in the hundreds of billions. And it still wouldn't work.
> I believe mass media dominate campaigns because of the sheer amount of money thrown into them.
This statement makes it look like you think one is correlated to the other, which I'm not inclined to agree with. Because there's a lot of money in politics, that somehow means mass media "dominates" campaigns, whatever that means?
I'm not sure what your alternative would be aside from information directly from the campaigns themselves (which is almost guaranteed to be skewed, if not incorrect).
I was thinking of self-organized citizens, in the way some self-governed open access projects on the net have established hierarchies (i.e. wikipedia). Everyone can be a candidate, people can judge their contributions almost directly, and thus be more informed voters. Politics in much of the west depends too much on who you know, and who pays you to pay old media pundits to promote you. The tech sector has barely touched the way politics is conducted (i believe mainly because geeks detest the way politics is run and opt to escape to libertarianism).'
I don't really think it's a big deal if online-voting servers go down. It's not like you have to pay billions to re-run the elections.
Edit: Not to mention the fact that as much as we like to pretend all politicians and millionaire slime balls, they're working people providing for their families. Very few are going to entertain the idea of running their campaign in an entirely different way because chances are they'll lose their job if they do.