I can't think of what needs can there be? Even if we need Windows 98, this can be substituted by an emulator running on top of today's operating system.
Even now? Strange. Its almost 9 years after i stopped using win 98. I tried win 7 on my pc but i'm still in love with XP
Most probably this OS is still used by those with very poor hardware, I can't think of another reason. I myself stoped using it so much time ago that I can't remember
One of my friends has the old PC and 98 os in it. He just can't replace with other OS because the system doesn't support any other OS except 98