Why the bad English?

What I don't understand is why scam solicit'ns & background material (such as dummy Web sites) are written in "Engrish" -- English whose grammar is bad or at least stilted in construction. Granted the scammers aren't native English writers, but you'd think they could afford better translators. Sometimes the contents follow a pattern of plagiarism I came to recognize from my students, who would copy and slightly alter existing material, but whose writing skills obviously didn't mate with those of the author of the original material.

Could the scammers be deliberately writing badly as a filter, thinking that anybody trusting enough to accept the bad English is likely to be a good pigeon? Like they don't want their time wasted by those they solicit?

Of course bad writing is not pathognomonic. A few years ago I received a poorly written e-mail ostensibly from a well known nearby business addressed to me as a member of Congress (which I'm not) asking to arrange a private White House tour by a foreign party of visitors. It looked like a scam, though I couldn't figure out the angle, so I pursued it. I decided to try to scam her by asking for a payment for my trouble. Turned out the original inquiry was a perfectly legitimate request by a secretary whose English writing (like that of many of my students, albeit they were natives) skill wasn't so good and who had looked me up and gotten confused because I had run for another public office -- so it wasn't just her writing skill that was bad!

I think you answered the question yourself there: English isn't their native language. It certainly is no tactic to weed out the 'smarter' people. For me, English isn't my first language. I think I can say I speak english quite fluently and I notice quite a lot of mistakes in their writing, but I'm sure that a lot of errors pass unnoticed as well. I'm also sure it is not hard to understand that someone with a poor grasp of english will not see the mistakes either. It is far from correct to state that all 'smart' people are good at english. You really can simplify it to just:

English isn't their first language, so they make mistakes.

There's nothing more to it.

Sure, but scamming is a business. You'd think they'd invest more in their business by hiring people to make better xlations or by learning the language better themselves. No different from burglars having good tools.

Some scammers do write good English, but most don't. And very likely, don't know how badly they do speak and write it.
Think of them as burglars who are happy to break into houses by smashing windows with a brick.

Most of them really don't know how bad their English is--in fact, they often take pride in their English skills! If it is "normal" to you, often you can't see that it is wrong.

Many of their victims are not from English-speaking countries, and they don't recognize the mistakes. Sadly, I have also seen many fellow Americans who failed to recognize the English as a red flag! We prefer scammers don't learn how to improve their scripts, as some victims are alerted by the language. Those of us who are scambaiters make it a point to never point out their English mistakes, and we encourage victims to do the same.

Perhaps another reason is when scammers copy and paste the text into the email body of the outgoing letter.. If a large number of e-mail messages are constructed in that fashion, any corrections that need attention would probably take too long. I'm under the impression scammers usually send mass-mail outs believing their chances are greatly increased in finding another victim. I think it's English is not the native language of many scammers.
It's like myself learning another language, I'd never speak it as well as the locals.

Most of them really don't know how bad their English is--in fact, they often take pride in their English skills! If it is "normal" to you, often you can't see that it is wrong.

That would fit with the widespread impression that con artists have big egos.