I think a lot of it too was the original cost of the machine. Paying 500 dollars to upgrade a 600 dollar amiga seemed very steep, while 500 dollars to upgrade a 1300 dollar PC seemed pretty reasonable.
That was basically it for me..
Also, it was cheaper than that for me to get my first 486.
At the time, there was a thriving "upgrade your PC" market, and I would help people upgrade, and frequently get the leftovers.
So, I had no problem getting a case, PSU, hard disk, even a VGA monitor (bad cable, I fixed that) for free...
All I have to buy was a motherboard and CPU, so I was able to get my first "doomable" PC (486, I had older PCs before that) for under $200.
Upgrading my Amiga at the time would have been something like $400-$500 for the accelerator, and then I still had to add memory...
(I can't remember, but I know when I looked, it was something I couldn't afford at the time..)
And that would have been so I could run a few games better, but most didn't get any improvement from it.
desiv