Originally this was my thought as well. The reason i like offering a toy project route is because I dont want a under-paid force labour exploitation happening. Basically where I get people to do real world problems for very low pay (bounties are meant to be bonuses not fair pay). WE could (not that we would) literally just have interviewees fix our problems at slave-wages if we forced them to do real work for bounties.
I feel like offering the option is nice, but can have the opposite of the intended effect when its required.