I think it's mostly an unintended benefit. These scams are usually run out of countries with English as a second language, so you get some grammatical errors in translation. It does increase the conversion rate, though, so they don't bother spending extra money getting a native English speaker to copy edit.

Yes, exactly this. You want people who can't see behind the simple facade. Because they are more likely to be easily fooled. You don't want to work someone who is very sceptical or just moderately sceptical. In that time you could work through a bunch of people that can't see behind this and pull out money from them.

Scammers want easy marks. Why wouldn't someone make it easier for themselves by naturally filtering out people that can't be easily fooled?

I'm sure that's some of it, but also I think a lot of it is this is the kind of crap you do get if you run Chinese through Google translate and just copy paste the output.

It's almost fine but then it falls apart and doesn't really make sense.