And the reason their orders execute in front of others' is because they offer the best price. If they didn't exist I would have to pay a little bit more to buy, or sell for a little bit less.
Is the full paper available without a login? Alternative matching schemes to price-time priority suffer their own drawbacks. Either there's no guarantee your whole order will fill (pro rata) or trade at all, and there can still be a speed arms race (there's an incentive to get your order in at the last possible moment before the batch to benefit from maximum information).
