Funny thread.
It's weather related, they are on their own. United's hub is Chicago, and the planes are very full out of there, even more so with delays. As we saw over the winter, one messed up day weather wise could have people stranded for days.
Over 500 flights were canceled in Chicago today, mostly due to low visibility. Not sure where you got your credentials to determine the weather was fine to fly, but apparently the airlines thought different.
The United States does have regulations regarding delays. They do not apply to canceled flights, and do not apply to weather related delays.
You can call, you can write, you can rant, you can drop the F word a hundred times. You will get nowhere, as it's a weather delay.