Why do people nowadays think tail end 90s culture is the representative of 90s culture in general?

That's it. The first two albums were not mainstream. Follow The Leader made them famous. In the mid-90s it wasn't even called nu-metal. In Europe the term crossover was common for bands which combined metal with rap or hip-hop. I think in the US they used to call them alternative metal. In the late 90s this kind of music was called nu-metal. I think the 90s consisted of three parts: the neighties, the mid-90s and the late 90s. The first years felt like leftovers from 1989 (till 1991/92). The next era lasts till 1997 and finalky there were the late 90s which felt for me a bit like the prequel to 2000. The 90s started colourful with its 80s-vibe and the end of the century was quite dark and futuristic. That's how I experienced this decade. In retrospective it was a great decade. There was also a big shift in technology. In the early 90s people were buying records and cassettes and at the end they downloaded music as mp3s.