A monopoly distorts. Preventing monopoly prevents the distortion a monopoly would create. Thus, it's an appropriate regulation.
That doesn't look correct. By definition, market distortion is considered to be
government intervention. In the case you describe, monopoly is presumed to be a natural occurrence in free markets, and through government intervention, we distort the market to make harmful monopolies less likely, or to regulate some of their more negative effects away. Monopolies are frowned upon when they take advantage of the market power afforded by the monopoly in abusive ways...too much power in too few hands, a common theme in human societies. But not all monopolies are abusive, and not all need to be broken up, some just regulated, and some left alone.
If normal free market profit seeking monopolies are considered distortion, then that would mean all market action is a "distortion", which would make it moot.
They just maximize total profit though, why is that so bad? I mean, all companies do that? Generally we expect competition...competition is valued because it means that power is less pooled. You have competition driving innovation, and keeping prices in check, if it's healthy competition. The system can just break if a monopoly gets big enough, and acts bad enough.
They key here is that all sources of power are kept in some amount of check, by other sources of power. They have to be in a sense, competitive, else, they may join together and be *even more harmful*.
I think the OP is correct, we have an entire population that has very partisan and very historically suspect ideas about our economy, and it would be nice if we could all be a bit more enlightened about it, and reap the rewards it would bring. If a monopoly naturally loses out to competition, no intervention is needed. Even knowing a lot of the basics, I still have huge gaps and misunderstandings. It's incredibly complicated...so people like to fall back on idealistic sound bites like "free markets are good, government is bad".