Metallica does a lot, infinitely more than Maiden, in the stuff that's not release or tour.
Interviews, specials, official bootlegs, celebration of past albums with huge new coverage, so on...I get they're public personas and Maiden is bunch of quite private dudes, but still end product speaks a lot. The disappointment SiT people received (and SSOASS!) with absolutely minimal new stuff on History 2, is something that does not happen with Metallica.
How would you respond to the same opinion about X Factor?