Yes, one of the reasons would be to keep the 1200 people on the train calm. It's important in an emergency for someone to be in charge of the situation. What's wrong with that?

Using a rough number for a yearly travel card, 1200 * £2000 = £2.4m yearly revenue from those passengers aboard that train. I think we can spare £60k for the driver.

Doesn't always work though. It might help but there are plenty of times where passengers take things into their own hands and follow survival instinct against the advice of a driver, both above and below ground.

During the July 7 bombings the train drivers led passengers out of trains and out exits. I would be glad to have someone familiar with that process on hand in the middle of that situation.

Actually, yes, British people do rather respond well to calm people with authority during a crisis.