Wow, what? IMO this article is way off the mark.
Regulation is not preventing beautiful homes. There are three things probably most detracting from neighborhood beauty in America are: a lack of regulations, capitalism and materialism.
All the places he lists as beautiful, especially in Europe have some of the most regulations regarding what you can build. A community design review, where a council literally has input upon the visual design of your building is almost unheard of in America but is common in European countries. The closest you get in America is some CCNRs saying you can't have a metal roof or the like. Parts of Switzerland literally require you to build a frame which represents the shape of the house you want to build so community members can walk by for some weeks and see how it affects the neighborhood skyline.
Capitalism has probably had the biggest impact. The reason older neighborhoods are beautiful because they were built at a time when practicing a craft was hugely important to a profession. You built those houses with all the mil-work and trim because that's just how it was done. Yes, builders were seeking to turn a profit but in many professions, a kind of cultural ethic prevented raw profiteering. That changed after the war. Post-war programs and an economic boom meant that you could start a business around moving shear volumes of houses. These builders hired people who weren't trained to think a porch without corbels was a sin. It's not just they didn't have the know-how. It's that they didn't think it was important or essential the way an old-school builder might. Modern American neighborhoods are what you get when profit is maximized and community input is minimized.
What people wanted in a house changed as well. The desire for material comforts like multiple bathrooms with indoor plumbing, loads of electrical equipment, forced air systems and more caused a good deal of the cost of the house to shift into equipment rather than aesthetic. The standards of home construction have gone way up too. From structural elements like the foundation to the quality of insulation to weather tightness.
Edit: BTW, I'm not saying one way or the other is the better way to do it. But if you want beauty, that requires a couple things: community review to increase coordination and enforced aesthetic quality. (These used to come from cultural sensibilities and now usually only are the product of regulation, HOA, CCNRs, ordinance, etc.) Both of these things requires the market to sell something people don't necessarily want to pay for.