Later the ability to run multiple programs at once became possible - the Mac got Switcher in 1985, then Multifinder in 1987, and there were various methods on the PC for running multiple programs at once.
Even though these were not preemptive multitasking, these solutions were viewed as "good enough" at the time, so there wasn't really that big of a gap with the Amiga.
Also, popularity - it was the early 90's before I saw an Amiga hands-on as a primarily Mac user - the reaction then was more "why would you want this low resolution thing" when SVGA and higher resolutions were somewhat common on both Macs and PCs.
I mean maybe a few people wrote letters for the letters columns of some magazines. It’s logically possible some of those letters were published some weeks later…magazines had lead times…and then a few issues later a response letter was published. But probably not.
OK, Usenet was also possible but in the 1980’s that was a few thousand people who could react in a way close to how we talk about reacting today. Otherwise ordinary arguing with people in meatspace was about the limit. You would have had to find other people with strong opinions.
It’s worth noting that in 1985, the C64, Vic20, ZX Spectrum, 8 bit Ataris, and Apple II were the ordinary home computers, not PC’s and Macs. On top of that the Amiga 1000 had limited distribution relative to PC’s and Macs (which in turn had limited distribution relative to C64’s etc.).