If you open a restaurant, you bet that there are certain building codes you'll have to follow in order to accommodate e.g. people with disabilities.
Right now, as the article points out, it's not something that most tech companies have to worry about unless they choose to, but perhaps it should be.
As startups disrupt entire industries with little regard for the existing legislation, entire niche of users could find themselves marginalized. For instance, hotels have to build a number of accommodations for people with mobility problems. Airbnbs don't. What happens to that segment of the population when/if Airbnb completely kills off hotels in a particular geographic location?
The web is already hell when it comes to accessibility concerns; and it seems like tech companies with a foot in the real world are just carrying this trend over. This is what people mean when they talk about the need for inclusiveness when designing tech products and companies; otherwise, you're just building a world where parents of developmentally challenged teenagers are even more excluded than they already were.
I agree with the core point of the article, but the example chosen to illustrate it couldn't be worse. Yes, it isn't your responsibility to solve everything for everyone, but that doesn't mean you can just choose to ignore the social contract altogether.