Why? It's not like any other airline/aircraft is going to be carrying more fuel then is needed for the trip. Doesn't mater the aircraft size, it costs money to bring fuel they don't need. Last time a US carrier ran out of fuel was something like 30-40 years ago. The reason they ran out of fuel was they were trying to troubleshoot another problem and didn't listen to the flight engineer saying they were low on fuel. One reason why Crew Resource Management came about.

Maintenance wise, they changed procedures to minimize the chances of something like AS261 happening again. They have gotten awards for their maintenance program for something like the last 8 years in a row.