If we assume that scammers live in the developing world, their time is almost certainly not valued so highly that having a few more responses to copy/paste a unanswered requests for payment to is worth their bulk email losing a single wealthy Westerner that's trusting and unworldly but also a stickler for good grammar (or has a spam filter that knows a lot more about Nigerian princes than they do). I've seen in-person scammers in the developing world continue to waste their own time trying to reel me in even after I've told them I'm familiar with that type of scam and failed to turn up for suggested meetups, and it's not like I was the only white person in Jaipur...

There are often horrible spelling and grammar and composition errors leading to phishing pages which involve zero further input on the spammer's part to collect valuable data too.