This isn't just -- they put it together and you click a button and suddenly you have your tickets.
This is "now you have to spend hours on the phone, attempting to book these tickets, and you don't have enough information to really do it -- nor enough confidence to pull it off".
So I love Flightfox and I hope they succeed, but I'm hoping to save time -- and Flightfox definitely doesn't. It saves you money at the cost of adding a lot of extra time to your booking process, but that's not a tradeoff that is apparent from the start, IMO.