I know what COBOL's data types are... I used to program in it in the mid 80's. My grief is not with its data types, but with its verbosity. As near as I can figure, the strongest (and I would suggest only) argument against using something like C++ or virtually any other modern native compiled language in place of it is because one simply has a pathological fear of anything new or different, and a belief bordering on religious zealotry (with often similar levels of refusal to listen to countering views or opinions) that no other language could ever do what COBOL does.
I get it that COBOL works.... but it's just so godawful tedious to actually develop in that I cannot see a good reason to use it today other than it may bring you a decent paycheque because you have an employer that still uses it. There's more to life than money, however... and it's possible to still make a good living programming in modern languages that are nowhere near as painful to use, so I don't think even that argument is a great one.