I think the only reason the PC Engine was used is because NEC had quite a long run of gaming computers that all began with PC, those systems weren't particularly well known outside of Japan but it was a pretty powerful brand when the PC Engine released rather than it being a description of what it could do.
I always quite liked the PC Engine but in some ways it was because in the UK we didn't actually hear that much about the system so for me it was one of those almost magical systems because it all just seemed so alien in comparison to other machines that were available. There was a certain romance to the machine, the name, the games that ran on the system.
Of course, it was also helped by the aesthetics and dimensions of the actual console, it just all seemed to be so futuristic, so different. The PC Engine core is one of the things that really sold MiSTer to me, I use it a lot and I'm so grateful for all the work that's been put into it.