Why do so many scammers use bad spelling, grammar, and punctuation?

I just got a text message asking to call a number and to relay bank information for a bank I've never stepped into. The Message was writton like This sentence , with misspillings , Random Capital Letters, and spaces before punctuation . I'm sure most of the scammers' English is limited, but at least make the letter or text message or email look more professional.

Point is if the letter or email from a bank has typos and errors, it is fake. No big business will send out unprofessional-looking letters or emails.

Because they are usually from another country and no grasp of the english language.

Be glad they do - it makes them EASIER TO SPOT

They do this to bypass email spam filters.

What you describe does sound like an attempt to trick spam filters.   But both Mike and LAMET are correct.  Much of the tele-scams and Email scams are from overseas, from non-English-speaking regions and, thankfully, their atrocious spelling and grammar  make them stick out like sore thumbs.   In fact it's one of the reasons a disproportionate number of victims of these scams tend to be people with limited English-speaking and writing  ability themselves.