Because he's not being fined £1.90 but probably somewhere in the vicinity of £500, and will now have it on his criminal record forever, similar to what happened to this man:

https://pbs.twimg.com/media/GZYx7QAXYAAM-y9?format=png&name=small

From the article, had you read it:

Mr Williamson said he could not believe an "innocent mistake over a confusing and opaque rule that only saved me £1.90, will lead to a punishment of hundreds of pounds and a criminal record".

UK train Corpos are some of the worst racketeering cunts on the planet with weird bullshit rules like this and this is after you consider that our transport costs like it's in Geneva but runs like it's in Karachi.