Here is one article which makes a similar point, and another which discuss the strategies of scammers and profiles of people likely to fall for scams. (I made the original comment and am not the lime who responded to your citation request). I will address your other comments on the topic here.

I can also offer my anecdotal observations about Nigerian scams from time I spent scambaiting when I was younger, back when I thought I was doing a service by distracting scammers’ focus away from someone vulnerable, and because it was amusing to see what stories they’d come up with.

• You were correct in saying that the opening messages would be copy-pasted stories with details changed.
• The stories had flaws and inconsistencies, lacked detail.
• Confronting the scammers immediately or refusing to switch to their platform of choice usually caused them to disconnect immediately. The excuses would come later when they were invested in a longer conversation and didn’t want to lose a potential victim.
• The general theme was that they are from a country other than Nigeria, or military sent overseas, stuck in a bad situation and need help. If I pretended to be male, there could be a romance angle.
• Sometimes they would admit where they are really from (confirmed with an IP grabber) but change their story and try to get sympathy by claiming scamming was the only way they could earn enough to survive.
• Gift cards were the initial payment method requested most of the time.

The long, elaborate (often romance and crypto-themed) scams you are thinking of are likely pig-butchering scams originating from China. Perhaps Nigerian scammers have evolved their strategies since then too; it has been years since I bothered to engage with them at all.

So no, I was not perpetuating a meme about scammers “preselecting stupid people”, nor did I say that everyone who falls for scams is stupid. Many are lonely, elderly, unfamiliar with technology, desperate, or kind-hearted but naive.