It is not actually a very bad thing for the whole market to go down for everybody at the same time. What is bad is for part of the market to go down, or for it to go down for some people but not others.
This failure highlights how frequent, scheduled testing of your failover system is needed in order to be able to say, honestly, that you even have a failover system, and not just another box burning power and doing nothing. When you have a choice, it is often better to have both systems running all the time, at less than half capacity and sharing the load; or each doing all the work, and throwing away half.
If you choose the former, traffic can sometimes peak over half capacity, without loss. If the latter, you can check that they are producing the same answers, too.
Every person's profit would have been somebody else's loss. They match exactly, less transaction costs which were saved by both sides. Of course somebody else didn't collect on the transaction costs.
The exchange obviously does not get to collect transaction fees for transactions it fails to mediate. But that does not harm buyers or sellers. As noted, they get a vacation from paying fees, along with avoiding any profits and losses.
The exchange suffers, paying salaries and rent without income, but they deserve it for providing crappy service.
This failure highlights how frequent, scheduled testing of your failover system is needed in order to be able to say, honestly, that you even have a failover system, and not just another box burning power and doing nothing. When you have a choice, it is often better to have both systems running all the time, at less than half capacity and sharing the load; or each doing all the work, and throwing away half.
If you choose the former, traffic can sometimes peak over half capacity, without loss. If the latter, you can check that they are producing the same answers, too.