"not winning a contract surely hurts, but it's not a loss"
I don't think you understand the situation.
In order to bid for a contract, time is spent evaluating and writing the specifications, and more time is spent evaluating at what price the prospect will accept your bid.
That time spent cannot be spent on other things, or other bids, or other projects. So, not winning a bid is indeed a loss. Not only do you lose the opportunity, but all the time you spent on the bid is gone.
There is no company that can survive without getting contracts. Something must cover the operational expenses. So yes, not winning a bid IS a loss - it just doesn't show up in accounting.