What a horrible assumption! It's not like they already paid for it with gasoline or other taxes!!!
Oh, wait...
“When new transit opens, people assume they will have to pay to use it.”
They don’t pay to use the road, the pay to ride the bus. The road is already paid for, as you point out, via taxes.
Of course, at least in our city, the fare only covers about a third of the cost of riding the bus, taxpayers pay the other two thirds.