Alas, none of these oft-recited dogmas bears any resemblance to reality. Shares rarely represent ownership. The float - the number of shares available to the public - is frequently marginal. Shareholders meet once a year to vent and disperse. Boards of directors are appointed by management - as are auditors. Shareholders are not represented in any decision making process - small or big.
The dismal truth is that shares reify the expectation to find future buyers at a higher price and thus incur capital gains. In the Ponzi scheme known as the stock exchange, this expectation is proportional to liquidity - new suckers - and volatility. Thus, the price of any given stock reflects merely the consensus as to how easy it would be to offload one's holdings and at what price.
Another myth has to do with the role of managers. They are supposed to generate higher returns to shareholders by increasing the value of the firm's assets and, therefore, of the firm. If they fail to do so, goes the moral tale, they are booted out mercilessly. This is one manifestation of the "Principal-Agent Problem". It is defined thus by the Oxford Dictionary of Economics:
"The problem of how a person A can motivate person B to act for A's benefit rather than following (his) self-interest."
The obvious answer is that A can never motivate B not to follow B's self-interest - never mind what the incentives are. That economists pretend otherwise - in "optimal contracting theory" - just serves to demonstrate how divorced economics is from human psychology and, thus, from reality.
Managers will always rob blind the companies they run. They will always manipulate boards to collude in their shenanigans. They will always bribe auditors to bend the rules. In other words, they will always act in their self-interest. In their defense, they can say that the damage from such actions to each shareholder is minuscule while the benefits to the manager are enormous. In other words, this is the rational, self-interested, thing to do.