There is a band called The Project Hate MCMXCIX that started in 1999 that has released 9 albums so far. The first album was great, and each subsequent album improved over the last. As you can imagine, their most recent album is a true masterpiece. They are the best band that has ever existed.
^That paragraph is almost entirely made up of opinions and my own subjective thoughts. A person who does not enjoy heavy metal would disagree with it. A person who does not like this type of heavy metal would disagree with it. A person who does not like this band would disagree with it. Are they wrong to disagree? No, not at all. They might simply dislike my favorite band for no reason, or they might actually have valid reasons for not liking it, but either way, they are neither "wrong" nor are they "right". No band can be named the "best" band, not even my favorite one.
That being said, I dislike Nirvana and do not think that they are especially talented at all, so I disagree with you on that one.