Organizational structure is definitely important for employee performance. How the hierarchy within an organization is set up will affect how well people are able to do their job.
But I also think that any limitations and difficulty created by organizational structure can be overcome if there is good leadership within an organization.
In the company I work for, the organization structure is very rigid. It's not easy for employees to communicate with employers and receive feedback. But we have a great manager in our department who works around the structure and puts in a lot of effort to communicate with us.
He doesn't treat us as inferiors but rather as friends. He asks for our opinion and includes us in brainstorming sessions. Ever since this manager has arrived, our performance as a department has greatly improved.
So I don't think that the limitations of organizational structure should be an excuse for employers for employee performance.