When did tweeting become a chore that had to be done at some specific time and number of times?

Are people really judging people on how often they tweet? If you have insightful things to say, or are contributing with new and interesting posts then it should not matter about how often you tweet.

The bigger the water hose != better the twitter account

In terms of too much noise, you can always filter users and content with lists. I am sure twitter is working hard on allowing users to create streams off their raging rivers.