'difficult' for the staff? Are you having a laugh! It'd give some of them something to do. The goodwill towards the community by allowing people to use the bridge surely outweighs the 'difficulty' for staff? They are paid.
As to fare evasion. It's pretty much impossible now, and evaders can be picked up at the other end.
I've written to the mp, network rail, and others.
It's a bloody disgrace of the station to be SO deliberately obtuse and unkind to the people of forest hill.