On Thursday, November 5, 2015 at 10:15:14 AM UTC, Offramp wrote:
We are meant to board buses by the front door and alight by the centre doors.

Why do old people only want to use the front doors for both?

The facility of egress would seem identical.

They are not identical as the front entrance on London buses normally has the ability for the front suspension to kneel so reducing the step up/down to the kerb. This is a major benefit to people with reduced mobility such as the elderly. Drivers are encouraged to look out for people such as this as part of their customer service training. So it's good to hear that this is obviously working!