You’re making the wrong comparison here, this is just a difference in facade with a three-story bump-out, it’s still a contemporary home. But perhaps you’re getting ahead of yourself with modern/contemporary - we’re talking about aesthetics, not architectural overhauls. Where do you see an ultramodern townhome community being built in DC? Look at the pictures in that link you sent. That’s obviously not the comparison point. Go look at what EYA is building at Michigan Park, look at NV Homes in Aspen Square - that’s what’s being built.

You just linked condos - Ritz Carlton condos, no less - what point are you trying to make there? That’s a completely different product and market.

The article you linked is misleading and not particularly relevant to this discussion. Of course that house costs more to build than a normal “traditional” house—its a custom built, high end house with a lot of custom details and high end finishes/appliances. When you’re talking about multifamily housing, “modern” developments are much cheaper because there isn’t as much decoration and the structure is far more efficient. If you wanted to build an exact replica of the townhouses in OPs post, you would have to shell out a ton of money for the decoration, partially because labor is more expensive than when they were built and partially because there are very few companies that could manufacture decorative elements at this point.

I’d encourage you to drop the straw man of the elitist architect too—architects in multifamily construction have very little say over what style the building will be—a combination of what the developer wants and what zoning requires determines the shape and style of the building. Developers generally speaking are incredibly conservative as well—they are putting hundreds of millions of dollars into a project and they don’t want it to tank due to a bad decision. If they want modern architecture, chances are that’s because the market wants modern architecture.