The user can enter the desired expiration time before signing the transaction. If the transaction is not included after a certain number of blocks, the block height is automatically rejected after the publication. The developers will be compensated regardless of the outcome of the project – and they know that… The difference here is that Decred never had an ICO and developer incentives are based on block rewards, which means the development team has an incentive to continue improving the protocol to maximize the value of those block rewards moving forward.