Try flying United some time.
A couple weeks ago I had to fly out to New Hampshire from Michigan. They connected through O'hare, then Newark, then Manchester. But Newark is doing construction on one of their runways and cancelled a bunch of flights.
I thought the United lady was being helpful when she said she could get me to Boston and shuttle me from Boston to Manchester via ground. Imagine my surprise when we landed in Boston: the shuttle cost over $100! Might have been nice if she told me that in advance, don't you think? I called United and asked for recompense, and they told me that it was an air-traffic control decision and not a United decision, so their policy was not to compensate anything. Nice.
Got in 6 hours late, cussing United all the way. Little did I know that the flight back would be an order of magnitude worse.
Waiting in Manchester for my flight, I got a call from United. Their flights our of O'hare were running behind, so I was going to miss my connection to Michigan. Again, an air-traffic problem was to blame, so she said I had to get my own hotel room. When I got to O'hare that night, they told me that they had one more plane to Michigan. So I waited. And waited. The flight time got pushed back one hour. Then two. Then three. Then, at 11 PM at night United came on and told us all that the flight was cancelled because of mechanical problems, and the co-pilot had 'timed out'.
They actually agreed to put us all up a hotel since this time it was 'their fault'. So what did they do? They put all of us on the flight, some 60 people, into the same fucking hotel that was over 20 minutes away. The shuttle held a grand total of 10 people.
So we all arrived at the shuttle area at midnight, knowing full well that the shuttle rides would be going on for FOUR HOURS to get us all to the hotel. Some people had to be back at 3 AM as the only flight they could get on was leaving at that time. I made it home the next day at 4 PM, only 19 hours late, and made it to my son's graduation with actually 45 minutes to spare.
I've flown North West and Delta and never had anything remotely like this happen - and when we WERE inconvenienced on those flights we were compensated. United absolutely sucks.