It's pretty clear what their purpose in giving tickets is, and most of us have probably been in situations where we've gotten tickets either completely wrongfully, or close to it.
While going to get my car out of the pound once, I met a guy who was there - he told me it's the second time he's been towed, he went to court, fought and won. But he's self-employed and has the time/flexibility to take a day and do that. Most people can't, so they go, pay the fines. And just carry on, and the city knows this, so they're overzealous about giving tickets. From their perspective, if they give 100 unwarranted tickets, and 5% fight it, they're still winning 95% of tickets they wouldn't otherwise get (read: they don't deserve even according to their own laws).
Yeah, I wouldn't be too upset about them losing some ticket revenue.