I'm not crazy about that, but certainly it'd work, and there would still be some savings. Due to the above mentioned stupidity, you'd still have no routes for some parts of the internet.
what i think it boils down to is that many folks seem to run default-free because they can, because its cool, because its what tier-1 folks do, because (insert cool/uber reason why here), but not necessarily because they HAVE TO. even if you're a content-provider in North America and want to ensure an "optimal path" of traffic, generally speaking, you could accept prefixes (as-is) from ARIN allocations but for (say) APNIC and RIPE do either some degree of filtering or just push it via a default. having a full feed may be cool, but i'm not sure what cost folks are willing to pay for that 'cool' factor. filtering and/or default-to-one-place may be so 90s but that doesn't mean its a bad thing. cheers, lincoln.