> Perhaps there's a term or a well known genre (besides "irony") for critiquing a writer by mimicking his style
Parody.
In fact, this is the strict definition of parody - the kind that's actually protected in copyright law.
Other things that get called Parody, like Weird Al Yankovic songs, aren't strictly parodic because they are using a creator's work to critique something else. Just changing the words to a thing or reusing the characters or plotlines to make it about something else isn't 'parodic' unless the something else you're making it about has some critical purpose in relation to the original work.
Using someone's own style to critique them is, precisely, legally, parody.
Parody.
In fact, this is the strict definition of parody - the kind that's actually protected in copyright law.
Other things that get called Parody, like Weird Al Yankovic songs, aren't strictly parodic because they are using a creator's work to critique something else. Just changing the words to a thing or reusing the characters or plotlines to make it about something else isn't 'parodic' unless the something else you're making it about has some critical purpose in relation to the original work.
Using someone's own style to critique them is, precisely, legally, parody.