[constantcrying]

Because there are conflicts of interest. Factory workers create the products which create profits. I am paid with these profits, if the profits go down engineers loose their jobs.

If Factory workers longer and more efficiently my job becomes more secure. So obviously I want a union which advocates that factory workers work longer hours, it is clearly in my interest. The same goes for strikes, if factory workers strike they endanger my job and reduce the size of the engineering department, reducing my chances to get promoted.