The profitability of a business is reduced by anything that undermines employee morale.
Conclusion (not wise / this is why)
Paying senior staff with stock options is not wise.
Evidence (because)
Stock options allow senior staff to earn more when the enterprise prospers. This dramatically increases the difference in income between senior staff and employees who are paid a fixed salary.
Profitability is reduced by anything that undermines employee morale.
Evaluate
We need to get from "paying senior staff with stock options" to "unwise".
They tell us that paying senior staff with stock options will increase the difference in income between senior staff and employees.
So the author is assuming that it's .
But the conclusion indicator "This is why" at the start of the 2nd sentence also tells us that the 1st sentence is an important part of the logic.
It's telling us that when you undermine employee morale, you reduce a business's profitability. The idea of "reduced profitability" is probably intended as a match for "not a wise policy".
So the author seems to be thinking that when we dramatically increase the pay disparity between senior staff and fixed salary employees, that will undermine employee morale.
The author's overall reasoning chain looks like this:
Pay SS greatly lower reduce not w/ stock → increase → emp → profit → wise pay gap morale
Goal
Let's look for that missing internal link, that .