Well. With such large firms, shareholders are quite a stretch of distribution. Voting proxies and the complexity of introducing a shareholder vote proposal quite drastically restricts the number of shareholders who can make stuff happen at these firms.
That is how ownership in a public company works. The more you own, the more control you have. Before you purchase, you will know what percentage you will own and you have to predict if it will be enough to enable you to accomplish your goals. Or you have to make friends with other shareholders.
