Most researchers are advocates for their work, but you're right that Wadler is more vocal and enthusiastic in his advocacy than many (but maybe less than others

Most researchers are advocates for their work, but you're right that Wadler is more vocal and enthusiastic in his advocacy than many (but maybe less than others, like Bob Harper). Programming language theory is unable -- and does not attempt to -- assign a value to languages, to say which is good and which is bad (even assuming such a value exists and isn't completely contextual); programming language theorists, on the other hand, can have personal preferences like anyone else. I agree that PL theorists, perhaps more than others, like to blur the wide gap between theory and practice, their preference and their research, sometimes even in a way that can detract from their work. As to confusion about types, you are also right (and I wasn't assuming anything). What types are in a formal language is pretty clear: they're syntactic derivation rules for determining which terms are well-formed by assigning them sorts. This is what theorists who study typed languages mean when they say "type". However, in programming types play several roles, some or all of them are also served by other mechanisms, like dynamic types (which are not formal types at all), and so there are different types of types.