I understand. It does seem a bit odd, but it could be that this is from before when the precision was so low - maybe that induced people to go with whole amounts. It's my preference too to just completely open the order book, but some of the devs disagree. But this is a big improvement at least.
Maybe because there aren't that many bots yet?
Another request: (Optional) email confirmations, once all orders are filled (per currency pair) would be nice.