The fact is that we live in a kafkan place where everybody seems to think that letting consumers choose what they want to buy hurts them, that delivering goods make a country rich, but receiving payment makes it poorer, and that a government picking winners on every market is the best way to ensure competition.
You'll certainly see several protectionist policies at the US, what is extremely annoying, because they claim to be a completely open country. But the US is still one of the less protectionist ones.
From the Word Bank data, there were 40 countries with lower median tariffs than the US, 4 tied with it, 71 with higher tariffs, and 98 without data in 2013.
Between the countries with lower tariffs there are extremely rich ones, fiscal paradises, EU countries (that have zero tariffs between themselves), and 4 poor ones.
Between the countries with higher tariffs there are basically the poor countries, and Australia. I don't think I've seen any other rich country there.
So, yes, the US is within the countries with lower tariffs. But also yes, every other country that you'll think of has probably lower tariffs than you.
They care about consumer freedom, that's why. What you are implying is that competition can never work and that people with a head start should be regulated away.
It screws the consumer and there is no proof it works best in the long run. France is super protectionist but they aren't doing so well. In many cases, it just has knock on effects that make other industries uncompetitive. Can't buy the best engines, therefore we can't compete in any market that requires good engines, etc.