I still don't believe these lists or calculations of concentration by address (as opposed to owner) mean anything at all.

One big factor is how much of  the coin is at exchanges (i.e. many owners, few addresses). Bitcoin has the best developed infrastructure for thin wallets, mobile wallets, hardware wallets, paper wallets, cold storage, etc. and is also somewhat less dominated by speculative activity (virtually 100% of activity for most alts) so it stands to reason that less of it would be held at exchanges.