Well, no I am not overthinking it, but it doesn't need it. Some Thai authority has determined that, to be worth the cost and risks for the country, a foreigner on a one year retirement visa should spend at least 65000 THB a month. And it seems that some can't fulfil this requirement and cheat the system. Zero thinking is needed here, is it?
Now when it comes to tourists, 65k is what most of them spend in 3 days. "Think" about it..