NM wrote:

Then don't sell the ****ing tickets if they can't deliver.

Given that the tickets I buy allow me to use any number
of routes, which might include Thameslink, how do you
expect to achieve that?

And the flexibility is incredibly useful. It allows me
to choose the best connection across London and adjust
my journey if, for instance, my train into London is
a little late and some other route will work better.