I've been driving for almost 15 years in the UK, and I've only been stopped once by the Police at a heavily advertised drink-driving checkpost set up during the Christmas season.
Discrimination does happen in the UK, but I don't think there's the same motivation from the Police to arrest people for trivial matters during this sort of campaign.
Certain systems are more efficient if they operate with high trust. The TTC is one of the places where we go with the more efficient option that allows defectors to gain at the cost of others. I actually know someone that is a communist and refuses to pay TTC fare on the basis that he thinks it should be completely socialized. He estimated that the one time he got a ticket paid for only 1/3rd or 1/5th of his total usage.
In other words, defectors are still net-ahead. The system is under-policed.
But the small amount of policing that exists exerts enough social pressure to stop widespread flouting of the rules. I was happy to provide proof that my very-soon-to-be-expiring transfer was from a valid trip.
I'm sorry that you've had a poor interaction with an officer, but I think it's partially a matter of how one treats officers. Even when I've been in the wrong, I did my best to treat them with respect and I quite honestly have been treated well by every police I've dealt with, save one exception when I was pulled over in America. I accept that this happens, and a curt reply and a stiff ticket is not the end of the world and I am happy to have largely lived and traveled in places where the police were civil.
Small "crimes" like stealing streetcar fare are sought out not because of the crime itself but because the more contact points people have with police the more people are arrested. There is probably an overlap of people who steal streetcar fare and people who are harboring small amounts of narcotics etc etc.
Just like in America we're pulled over on the road for the most benign things just so there's contact with the police, which leads to a higher rate of convictions.
I was doing self-checkout at Walmart and the dumb machine thought I stole something I had already scanned, lo and behold an officer appears out of the shadows with a general attitude at me as if I was trying to pull off the grand-heist of stealing GREEN ONIONS.
I personally think law-abiding people have a right to limited contact with police.