I don't quite understand the full argument that you are trying to make. You seem to assume that it is more justified to "protect someone from themselves" than to "protect stupid people from loan sharks", and that the situation at hand resembles the latter more than the former.

To me the justifiability of these two imperatives seem to be reversed. But to the extent that "protecting stupid people from loan sharks" is unjustified, we also think that we should "protect weak people from robbers and bandits", and protect people from frauds.