I think it's more than just stuff being cheap and available. It was also a very special time, the internet was new and not everyone had access to it or knew how to use it. Showing off your modded case was a huge accomplishment - not only because you spend so much time and money on creating something unique, but also because you had very isolated communities with only people who had the same interests as you.

Nowadays, where do you share? Reddit? Twitter? Facebook? It's so public and you have to compete with people who spend 3k on their PC, 1k on a keyboard, nice periphery, table, monitors and room LED lighting.

I'm sure there is more to it, but that's at least how I feel about it now.

Edit: Oh wow, thanks, didn't know bit-tech is still active!