I mean, if you post MBTI type of _ on a website like Reddit or Personality Cafe, versus annyomously typing someone here, it's different.
Here you can theorically type someone based on what you're thinking at the moment, on first impressions, etc.
Especially typing characters in sit-coms that are longer than 7 seasons. Characters change, flanderization, etc. It's not surprsing that the first 5-6 seasons some of the main characters resemble Type A (let's say its ENTP) and after some flanderization, that character resemble Type B (let's say its ENFP or whatever).
Also the posts like "Least materialistic type" or "Type that hates 6w7" or whatever. I mean, it can be used as a general measure, where if you know someone you're 100% convinced is a certain type and he is not materialistic at all (minimialism or whatever), that may work but overgeneralizing could cause problems.
This may be a flaw of Extraverted Thinking. XNFPs and XNTJs, use extraverted thinking. Some XSTJs are here commenting in this website. I don't see so many XSFPs here in the comment section though.