It's possible that:
* He does like Nirvana: It's a very popular band, and many people of his generation enjoy their music.
* He doesn't like Nirvana: Music preferences are subjective, and there's nothing wrong with not enjoying a particular band.
* He hasn't publicly stated his opinion: He may not have discussed his feelings about Nirvana in interviews or on social media.
Ultimately, it's best to respect the privacy of celebrities and avoid making assumptions about their personal tastes.