I think you would do better to look at the statistics than a single case example...

Behavioural science has miles of data on the impact of reinforcing negative behaviour... I don't think this is any different from that.

Cheating is negative behaviour, I can't imagine anyone would argue with that. But reinforcing it with friendliness?

Behavioural science has shown what happens there.

Look at your kids... What's the parental science advice when kids behave destructively to themselves and their family?

Be nice? Is that the current parental science theory of the day?

And I haven't even mentioned the word addiction yet...