Getting paid properly is important of course, but intrinsic motivation (of which a sense of autonomy is an important driver) is very important to keep workers happy, independent of whether they're doing crowdsourcing work or just a regular job.
I find it hard to believe that this platform will be competing against Amazon Mechanical Turk on price, so they'll have to compete in other dimensions. Increasing worker motivation to improve the quality of the output is a win-win for all the stakeholders, so IMO it's worth pursuing.