I think I remember the logic behind this. The end user requests provider independent addresses, insisting that they would sue the registry if they didn't get them. The draft discourages this and so the registry should discourages this but the draft lets them give in.
Actually, the logic was from multiple ISPs who told us it was imperative in certain instances (as noted in the draft) that multi-homed organizations be given PI space. The registries (although I officially speak only for InterNIC) continue to discourage multi-homed customers from getting PI space.
Just to make it unanimous for the RRs, APNIC also discourages PI as much as we're able. However, with respect to reasoning as to why we continue to allocate PI space (regardless of whether it is multi-homed or not), please see RFC 1814. I would find it really interesting to discover how much of the current routing table growth is due to newly allocated prefixes getting announced and how much is the result of a) previously unannounced but allocated networks being injected or b) entropy resulting from movement of networks from one provider to another. In my copious spare time... Regards, -drc