> Businesses should be allowed to create whatever products they want, as long as they don't do anti-competitive things like work together with their competitors to fix prices.

Or say, if they owned a huge marketplace and eventually started producing a product, and then refused to stock their competitor's product in the huge marketplace.

Do you demand that the local supermarket carry every brand of chili on earth?

I don't think that's a good analogy; there are significant differences between a local supermarket (local, items must fit in the store) and Amazon's marketplace (global, items can be located anywhere globally within reason).

The justice department(?) demanded that Microsoft stop bundling (or forcing, can't remember the specifics) IE on Windows.

Laissez faire capitalism has both benefits and risks, casual/militant dismissal of concerns can sometimes have negative consequences, sometimes very severe.

>> Free markets are important.

There aren't free markets in a pure sense and it's a good thing:

- Standard oil was broken into exxon, chevron, etc...

- Laws were introduced to prevent railroad barons from owning every industry by forcing fair treatment.

- Electricity producers aren't allowed to sell directly to their customers in many countries. They are forced to sell it to resellers.

>> as long as they don't do anti-competitive things like work together with their competitors to fix prices

That's subjective, What does anti-competitive mean? it could mean making cheaper competing products as a retailer. It could mean refusing to host your product just like it happened to chrome cast. It could be ranking competing products lower.

Amazon is in an unusual place of both controlling the market and entering the market however. That doesn't really fit with the nice simplistic ideological "Free market" concept. It's hard to see any motivation for them not to game the system if there's no regulation preventing it.