The Need to Categorize Supernovas

There's a range of brightness for supernovas and typically I thought all supernovas were all sort of the same. But there's something else going on here which is this astronomical need to like categorize. It's not just that there's a distribution and these are the ones on the tail. They feel like they see this cluster this collection of supernova that are different from the other ones. And so why can't you just say well here's supernova summer brighter summer dimmer?