The problem with buses is that they are often only decent value if you are under, or over, a certain age.
Outside the peak buses tend to mainly be used by Under 16s and Over 60s.
Why would I pay £3 for a return to town, when I can cycle in less time, for next to nothing? (My bike cost me £350 and has required no maintenance for 2 years - that works out at 47p per day so far and it has plenty of life left in it)
Where there are parallel rail routes, a Y-P discounted return is nearly always cheaper than a bus fare (in my experience), despite the train being quicker - where's the logic in that?
To make matters worse, buses are full-fare for anyone who looks 14 or over in places like York, unless you have a York-specific card (not just general proof of age card).
I only ever get buses when I am forced to do so due to being outside my home city, and going to a destination not served by rail. Last time this happened I was refused entry to a bus due to it being full, causing an eventual delay of 2 hours (as I missed a train as a result). Many of the people on the bus would have been 60+ travelling for free and been home before I'd even got on the alternative bus I had to get. It's not fair, but then I can't complain because there's no-one to complain to!
The bus industry is totally unaccountable, makes up random rules as they go along which differ hugely from operator to operator, there are no customer charters, no compensation schemes, no nothing.
It is for these reasons that all proposals to replace rail services with bus services should be opposed.
Of course buses are cheaper to run - because the companies can screw the fare-paying passengers and not have any concequences.
But back to the question, I really don't have an answer, but something isn't right when fare-paying passengers are turned away.