>>46452550Probably for the same reason that Bethesda ignores New Vegas. They were good, and made by a different company, and they actually had thought put into them. Gamefreak were probably butthurt that they got upstaged by some literally-whos.
It's a shame we don't get non-mainline pokemon games like this anymore. Not being part of the main series meant that they could take risks and do something unconventional. Not to mention having an actual difficulty curve instead of being piss-easy. Colosseum wasn't perfect by any stretch of the imagination, but it was unique and worthwhile.