It may not be but it's the truth.
Startups are successful because the very nature of survival depends on the success of the one product. Now if they have a good idea and they find the recipe to be successful, they get a good product.
When they are successful, it's often unexpected even by the founders. Then they expand. And the accountants and the sales guys get promoted, because for the most part they are more charismatic and extroverted than the engineers and it's easier to see success as a dollar sign than "good engineering".
Then eventually the company gets run by finance guys, because again that is the easiest metric to judge against.
And it won't change. Because even though there are those that resist the influence, the vast majority change for the worse.