Linguistics is a descriptive science. There's no such thing as "prescriptivist linguistics".

Rather, there are prescriptive grammarians. These are typically not linguists, but rather professional writers or literature scholars who have strong opinions about "correct grammar" in their language, and instruct other people about it.

We have prescriptive grammarians in English too, like Lynne Truss (author of Eats, Shoots, and Leaves) or the famous Strunk & White. However, we typically don't give them government jobs doing their hobby; we just let them do it privately.

I Spanish, the Real academia de la lengua is often used incorrectly by people as a prescriptive reference but what they really do is gather the common usages and incorporate them into the language. It's like a descriptive record of language.