And there ya go, you described the valid rationale for the hype yourself. Obviously both the STI/EVO are dead and you get modern systems like ACC with better fuel economy and safety.
Add on the fact that the Type R isnt enough of a change over the FK8 (lets be honest here too, the general type R demographics probably prefer the overstyled FK8 for 10HP stock difference, we have to see how it tunes). Then you have the MK8 Golf R which is better but people seem to have too much rage against the capacitive buttons to see the good in it, plus arguably a lot of the hot hatch people will only buy JDM because "reliability" (DI is a good argument against but a lot of anecdotal reliability claims persist these communities as gospel).
So yeah, the GR Corolla is hyped because on paper it really is fantastic considering the market. Maybe if the RS3 fastback was in America we'd have some other opinions considering huge ADM but as it stands Toyota has a pretty clear launchpad for the GR Corolla to be a ringer. Economic distress non-withstanding of course..