"Ethical sourcing and labor agreements"
Right... Just like Apple. Exploitation of labor in emerging markets is a hallmark of industrial progress. If it's not China, it will be Bangladesh and elsewhere.
Mass-produced items such as tennis racquets are not immune, even those firms who have "ethical" agreements with labor in the countries in which they operate.
Wilson suffers from the same quality control issues as any other huge corporation and, yes, there is a correlation. It's about lowering costs and increasing profit margins.
And, if you really want to get nitpicky, the use of machines in certain factories leads to even lower wages for non-automated factories. I'm not suggesting that technological unemployment is inevitable, but in the face of losing one's job, the willingness to take a pay cut, work longer hours, etc is difficult for an individual to refuse.