it's the opposite. scammers want the people that are gullible enough to go for "free"

This is a narrative I've heard many times, with very little evidence to back it up. An alternative and more accurate view is that, as the world came online, people became exposed to the very low-effort scams, representative of criminal elements from around the world, which befuddled most due to their child-like naivety. None of those confused individuals would fall for it but they require an explanation. Someone came up with a theory that it's actually a stroke of 4D genius and it stuck.

edit: ok, I bothered to look this up: Microsoft had a guy do a study on nigerian scams, the guys who wrote Freakonomics did a sequel referencing that study and drew absurb unfounded conclusions, which have been repeated over and over. Business as usual for the fig-leaf salesmen.