I share your frustration, but we have to accept the economic facts. It costs most of the selling price to manufacture a phone. New phones may not be a success, and the manufacturer (as distinct from the designer) knows that if they are not sold he won't get paid. So they want the full price up front before they make any phones. One+ is a new company and doesn't have bags of money to pay the manufacturer. What to do? They start small and pay for only a few phones and invest the revenue in the next batch of phones. If all goes well it will cascade into an avalanche of phones. If nobody buys them they go bankrupt, but the actual manufacturer is ok as he is paid before he makes anything.
Frustrating, yes. But only Apple has the deep pockets to buy enough to satisfy (most of) the demand on release day. So sit tight and your time will come. Or buy something else now.