Why shouldn't they?
That's how pretty much every organization works. Every military, every government, every sports team, every space mission, every classroom, etc., they all have some person or small group up people with more more decision-making power, or "more say," as you put it.
I fail to see the problem with that. In fact, there's a very real benefit in that it's generally more effective. For example, today people are completely free to create organizations that work differently, and they rarely choose to, and when they do, they rarely out-compete the alternative. So the proof is in the pudding that there's something less effective about it.
If I had to wager a guess: decision-making isn't something that scales well. Bodies might have dozens of organs, but they only really need one brain to control them all.
> They will eventually die or sell their share, and in either case it will end up with people who care less about the company's long term health than the founder did. Profit maximizers with no ethics and no feeling of responsibility.
1. There are plenty of counterexamples where the leader of a company ensures its long-term success after their tenure ends.
2. Even if this were somehow a downside of owner-led companies, you always have to ask the question, "...compared to what?" It's not like the alternative doesn't have its own slew of downsides, as evidenced by the dearth of competitive co-ops that compete successfully with owner-led companies. In other words, organizations are always going to have issues and errors and flaws, no matter how you set up decision-making.