Occam's razor says they are just bad at English grammar because it isn't their native language/dialect and their education probably wasn't that great.
This is easily demonstrable by conversing with the scammers and noting that their actual English ability is the same as exists in the initial letter. Even when they have no chance of the scam succeeding and have been outed they write the same way. You can see plenty of evidence here:
Occam's razor says the sun orbits the earth, everybody dies from Sudden Unexplained Death Syndrome, and the correct way to spell Occam's razor is Okams Raza (in all languages, because lavishes other than English are difficult).
It's literally a platitude. It's like the saying 'when the going gets tough, the tough get going': it's reallyemorable and descriptive and is maybe a good guideline in many situations.
But using it to evaluate the tensile strength of various metals according to their velocity would be wild, because it had never pretended to be anything like a rule. It's not like theory of gravity or 'I before e except after c', which are based on actual analysis and results.
Legit assuming that everything is as simple as it can be, that the most obvious idea to occur to any untrained observer is the most accurate, is literally a guaranteed way to go though life without understanding anything, at all. Using it to argue with people who appear to obvious what they're talking about (and there are so, so many undisputed studies on the exact reasons scammers do what they do: it's too filter people or. There is no debate, academically) is a pretty slippery slope to 'anybody who doesn't think and act exactly like me is lying, because no reasons or facts exist unless I personally hold or after with them', and it's definitely a thought process worth challenging.
Although to be fair, its best application might be re. online arguments that you don't really care that much about. So if you just meant that the previous poster had given a reason and you were going with that because it's easier, my bad.