Unless it turns out that profits are directly proportional to creator happiness, why would a for-profit company use that as the primary metric in deciding the compensation of managers?
I am willing to bet there is correlation between the two, but not enough to make it as a primary metric.
As I recall from my business management classes in college, no studies have ever shown a correlation between worker happiness and productivity. That doesn't mean that happiness has no effect on other metrics - but this subject has been studied in depth for the last century and researches keep getting the same result.
It would be absolutely silly to use those studies as an excuse to ignore worker happiness. My guess is that those studies are overly simplistic and difficult to draw any real conclusions from. Happiness is notoriously hard to measure, for starters, and productivity can mean a lot of different things based on the industry and type of business that's being examined. For instance, how do you measure the productivity of your software engineers? Lines of code? Features shipped? Hours worked? Many, many attempts have been made to do this and none of them, to my knowledge, have been particularly successful.
I think this is one of those cases where until we know with confidence one way or the other, we should probably just start out with the assumption that worker happiness is a good thing and put the burden of proving otherwise on the scientific community. Until then, let's go with our gut.
I am willing to bet there is correlation between the two, but not enough to make it as a primary metric.