Based on my limited digging and Maven plugin knowledge:
I think fixing this is tough (well, it involves a difficult decision) because there appears to be a design mismatch in how the archetype plugin operates and how Maven itself operates. Maven operates based on a LIST of remote repositories: the user may or may not use central, and all servers are filtered through the mirrors list to arrive at a final list of remote repositories. However, in the final remote repository list, knowledge of which repository maps to central (if any) is lost.
The archetype plugin is hard-coded to look at exactly one remote repository, central. There's no good way to resolve or map central to some other repository (not without some bad hacking) – exactly which remote repository from the list should map to central is unknown.
So I think the ultimate question is: Should the archetype plugin really be hard-coded to look directly at one repository, central? Why not utilize the list of remote repositories that core Maven already provides (already filtered through the mirrors), searching each one by one?