Corporate Culture Is Killing Innovation

I saw a documentary on TV that was looking into innovation and change in corporate circles, and amazingly, the High-ups (CEO's etc) actually seem to want innovation.
As a worker all my life at various levels within different companies, I had exactly the opposite impression.
In the documentary, it was stated that 75% of all employees are looking for a new job, and for the higher executive positions, the figure is at around 80+% , I think it was 87%.
This explains a lot.
I have, throughout my life, wondered why when I have a great idea, it is just brushed aside by my boss, and seldom exploited. Now, to be realistic, I know that some of my 'great ideas' are maybe great only in my own mind, and that in reality, the usefulness would be limited by factors in other areas of the corporation.
But probably the main reason for the rejection of innovation is that the people receiving the information are not interested in it, because they are not interested in ANYTHING.
This might be why they act so stupidly, and show little commonsense, other than to give the impression to their specific boss that they are doing a great job.
Looking at it with the knowledge about how most employees are looking to work elsewhere, I can now see what is happening.
If I have a great idea, and I tell my boss, this will mean more work for him/her. It will additionally introduce a budgetary demand, even if only for the time spent presenting the idea.
So, from a purely selfishly personal point of view of anyone in the corporate structure, it has no merit, only liability.
The innovative companies will be those who are innovative at the top.
All others can never have true innovation as it will be stalled at a low level due to personal agendas.