The problem is that an accountant can't see how employing staff/guards/RPIs for almost every train would make them more money.. To them, the RPI would pretty much get rid of fare evasion, thus they'd eventually get no fines.
To an account, the RPI is now a waste of money - nobody is evading anyway. Said accountant can't accept that it's only becuase the RPI is there, so when s/he goes the fare evasion will begin again.
The fact is, in this country (and many others) people have grown up not to do the right thing, but do whatever you can get away with. That's why we need to enforce everything instead of just hoping people will respect the rules - and fail so badly, which only helps to let everyone know you WILL get away with it.
Take other countries where people have pride and respect and don't need police everywhere. Japan is incredibly clean and crime is low (not non-existent, but low) and that is very much down to a difference in culture.
Anyway, I'd like to see gates AND staff. Yes, platforms must be announced more than 5-minutes before at a main terminal (that should happen anyway, as not everyone is able bodied and getting to platform 11 from the main concourse), and when people are caught for trying the little tricks like getting a cheap ticket to get through the barriers, it's a day in court and a criminal record.
Oh, and smartcards beyond London, so the gates will be much faster to operate than people faffing around with paper tickets (especially for the poor sods who got 101 tickets with their family advance booking on East Coast with a separate ticket for just about everything and will spend 2 hours working out which tickets to put in the gate).