I think many people enjoy being CEO for the same reasons people enjoy founding startups or going into politics. You say, "aside from the prestige, power, and money, it's not fun." If someone's job provides all three, I would say that they are doing pretty well!
Also, CEOs that focus on quarterly numbers do so only to enrich themselves (via stock options) to the detriment of the company. At my own company (a large test and measurement company), our leadership constantly makes big changes based on the stock price. Since my company pays no dividends, there is no "shareholder return" to maximize. My company will never do an additional offering so steering by the stock price doesn't make sense for the company in the long term. We are constantly delaying capital purchases to make the numbers look good. In reality, these delays cost our project's schedules to suffer. That hurts the company.
By focusing on quarterly numbers, who benefits? It may help somebody make a buck that quarter, but why should the company want to help traders? True investors think long term. It is the management team that is benefiting. Shareholder value is a myth. The only shareholders that matter are the management team.
I usually don't get too worked up about CEO compensation. The only things that don't make sense are massive golden parachutes like the former CEO of Home Depot had and paying executives in stock if they meet quarterly numbers. A company's vision should be long term. Making executives excessively interested in the stock price is dangerous.