Yes, the power of anecdote over data. The vast, vast majority of people who receive these benefits use them as intended. I know that it's virtually impossible to get people to stop letting their day-to-day interactions inform their position on welfare benefits, but please at least try and look at the program as a whole, and not individual uses of said program.
That's why the key is to help people understand the cost and benefits of the system overall and not try to change their perspective on individuals.
If the system is effective for the vast majority and the cost of those abusing the system is less than the cost to prevent the abuse then that's generally a win. (Of course you have to be careful of second order effects and unintended consequences. If people can easily get away with abuse will abuse of the system grow?)
In other words, you don't need to convince people that abuse of the system isn't wrong or that it is impossible, i.e. the "don't judge" comments, you need to convince them that the system is effective in both costs and outcomes.
