Why did microcomputers die off?

I think I'm missing something. For the sake of differentiating between, I'm going lump the Altair's, SWTPC, etc. into the Microcomputer group, Apple II's Atari's etc. in Home Computers, and IBM PC and compatibles in IBM PC group. I have a question. Why did microcomputers die off? I've been thinking about that this morning and I seem to be missing something. To my experience, the microcomputers started to really fade out around the time home computers got big. But to me these are two different market segments with some, but not a whole lot of overlap. Had the microcomputer market hit saturation by that time? That's the only thing I can come up with. But then what sustained business until the IBM PC steamroller came along? I guess it was mostly the unglamorous and unreported on microcomputers, as I don't think the Apple II got /that/ deep into businesses (other home computers had next to no penetration). Ah, hmm, maybe I am over generalizing the microcomputer group. Maybe it should actually be split into two, the hobbyist micros and the business micros? While they tended to use the same machines, the focus was different I think. That would tend to agree with my supposition above that the hobbyist micro market hit saturation, and the business micro market quietly chugged along until steamrolled. And that would imply that the home computer group had next to no impact on either of the microcomputer groups. Or am I missing a piece, or two, to this puzzle? Thanks, Brad