My last 486 was a 133 MHz AMD with 32M Ram, and that machine did run NT 3.51 fairly well as a file server. AND POP and SMTP duties briefly, and thats when I found it had limitations. NT simply was not designed for a 486. It may run on one, but thats hardly the ideal configuration.
Software bloat is a problem that is being addressed just in time.
For whatever people may be saying about Larry Ellison, I think he has the right idea.