Bus Fare

I just don't understand about the
bus fare charges thingy..
Who on earth came up with this?
If you are a secondary school or
a pre-U student, your ez link fare
would be 45 cents. If you pay by
cash, it would be 55 cents.
That's acceptable and affordable.
But i have a strong disapproval
with the adult fares..
The adult ezlink fare is 80 to 90 cents.
But if you pay by cash..
Gosh!! Goddamn, it's $1.50.
It's total crap lah..
To think that buses are seen as
a necessary medium of transportation
for most of us who don't own cars.
To think that the demand for buses
is price inelastic, which means that
a change in price of the bus fare
would lead to a less than proportionate
change in the quantity demand for it.
To increase their total revenue and
maximise profit, they jolly-well
raise the price of bus fares.
What's the difference between
ezlink fare and cash-bus fare?
What's the BIG difference that there
is a huge difference between the price?
Are they doing all these for their
own benefits or for our own good?