I think it's mainly me that wants paralax, though I'm sure the others do as well. For me, it's because the PCE technically can't do paralax, with only 1 bg layer. But, like with other systems that have this limitation(NES, C64, etc.) we find a way around it! Basically, it's refreshing to be able to do something on the PCE, that the PCE can't do!
Plus it looks nice, & who knows, maybe it'll shut up the MD & SFC naysayers that rip on the PCE for not being able to do it.
Either way, I consider it icing on the cake!
Edit-And hey, you got paralax in your game you're working on