Easy 10
Brain dead MUG SHEEP
Why not make the charge realistic and in line with the amount of "taking the p*ss" that is occuring?
Cos you're dealing with computers which apply automated charges. Same for everyone, as per the Terms & Conditions when you open the account. Whether you're a long-standing customer who has been with the bank for donkeys years and never goes overdrawn, or a fly-by-night chancer who's finances are all over the shop, in terms of charges levied, everyone is treated equally. They have to be. And it has to be enough to put people off taking the mick - because a lot of people will do exactly that.
Course when it comes to how much leaway you get with the bank when you ask them to waive a charge, it'll largely depend on your previous account conduct (unless the lawlords still override this anyway).
Anyhoo, I'm not preaching anything. You run your account how you see fit. I'm just giving the banks point of view on this, as I used to be on the other end of the phone dealing with this kind of thing. And the number of people who blame everyone and everything except themselves for the state of their bank account never ceased to amaze.