Internet polls are significantly different from Amazon turk; see my sibling post. Internet polling isn't nearly as problematic, especially for a study like this.

crowd-sourcing platforms need their own bias adjustments and I'm not even convinced that it's possible to adjust for the bias caused by using these platforms, unless you really are interested in putting a lower bound on human ability. Not a statement about the quality of people on Turk, just the amount of effort they often (rightfully!) put into below-developed-world-minimum-wage work...