Why are Hondas superior to American cars like Chevy & Ford?

Is it due to superior design, parts or quality control?

Not conceding the point, but you do realize that Honda doesn't design its own cars, right? For the past several decades, a company out of Turin, Italy has been designing Hondas. Remember when Hondas used to be totally fugly? That's what they looked like when they were designed in-house. Honda wised up and realized it couldn't design for sh*t, so it started outsourcing its design process. That's when Honda sales took off.

When your Civic breaks down, the Crown Vics will still be running.

For decades Honda was careful not to put in features that could come back to bite them. For those same decades, up into the 1990s, none of the American automakers were focused on durable passenger cars. That led to the perception you have - there were still shameful common failure points in Hondas, notably the fuel pump relay ("main relay") that failed in nearly every Honda made through the 1980s and 1990s but the American makes had more problems.

Recently that changed but the legends lived on. Between 1998 and 2004 (tapering off in 2005) the Honda automatic transmissions coupled to 6 cylinder engines had an atrocious failure rate, earning the 2003 Accord the second worst rating in carcomplaints.com ' s records. In 2006 Civic engines developed fatal cracks, the result of casting porosity. In 2008 the Accord rear brakes had horribly short life; some people had the rear brakes replaced every other oil change. It has been ten years since Honda has stepped on it with golf shoes, finally taking them off my "do not buy new" list.

In the meantime, Chevy and Ford have been stepping up their games. Ford introduced their engine temperature management system, making cooling system failures that will ruin the head gasket on any Honda survivable. Chevy is at least as reliable as Honda now - each have a few model years with headaches but mostly Chevy and Ford are better values (good quality at a lower price) today.

They're not.

30+ years ago Japanese revolutionized the idea of assembly line manufacturing with their "lean" methods. The result was higher quality at lower cost, so at that time, Japanese cars such as Honda and Toyota were providing better value to consumers by offering a car with similar cost but better long term reliability.

Those days are long gone. All car manufacturers worldwide have mostly adopted the Japanese manufacturing concepts and American manufacturers have closed the gap on quality.

Statistically, your odds of a Toyota Camry making it 200k miles without a major repair are equal to the odds of a Chevy Malibu or Ford Taurus if all cars are treated with equal care and routine/scheduled maintenance.

There's still some perception that Toyota & Honda are more reliable, and therefore those cars sell for higher prices on the used market, but the statistics no longer back up that perception.

All three reasons you mentioned are true. They try harder because of the cultural difference. In american culture big companies just want to make as much money as possible as fast as possible and don't care about their customers. In japanese culture they would lose face if the quality was bad, they want to offer the best product possible to have a good reputation among te customers.

Honda doesn't compromise on quality design and engineering.

Only manufacturing

All of the above.

Ww2 bombings happened. So they had to rebuild and retool their factories again. So they built modern factories with the latest robotics. That way they eliminated the human element to fug up the car. Hangover Mondays and let loose Fridays do not exist for machines.
. Then they only had to design 1 car. And put the specs into the machines to make the car. So car 1 and car 568723 are identical. And the factory worked 24/7/365 with no smoke breaks and no coffee breaks and no lunch breaks, no sick days. The Asian worker puts a higher degree of pride in their work. As there job has changed from assembly worker to inspectors. They were competing against German quality and have surpassed them.
. Less mistakes = better product.

In the US, they did not get bombed in their factories, some which were once barns. So all the work was done by hand, so everything stayed the same. Mistakes happen by people, people get bored, people have a hangover, people doing drugs, Boredom is the biggest reason for problem cars, New employees have not got the full instructions yet so they miss stuff. Workers care less. Their Unions will make sure they do not lose their jobs.(no matter how much they fug up). Unions did not want mechanization in the auto industry as many workers would lose their jobs. "That is what the Union says" but the fact is machines do not join Unions or pay dues which would cripple the Union heads from the big pay check they get… From the many member dues.
. So they take care of "themselves first"

Germany also got bombed but some of its assembly line factories were partially there so they did not go into mechanization as hard as Japan did. They did a partial mechanization, and kept with the same model for many years… Hardly changing it.
Less changes= more consistent product they could "tweak" to improve it.

Many car companies do not design their own car. FORD or GM or CHYSLER brings out a new model with sleek EUROPEAN LINES. All car companies are getting the car designed from Turin or other design house. Early Camaro, Mustang, Barracuda Muscle cars came out of European design houses.
The Ford Torino comes from Turin, Italy.