It may not be intentional, but poor grammar/spelling mistakes have been argued to be a feature, not a bug, of phishing/scam emails. i.e. people who notice these sorts of things and immediately have BS alarms go off, are not high-value targets because they're less likely to be fooled/convinced, whereas the sort of person who glosses over those errors and says "this seems legit" are exactly the sort of person they would like to try to scam.