A counter to that analogy is that where/when ramp access is needed and how one should be built in order for it to be usable is defined by building codes and the concept is well understood. Without what clear definition or a method to get a website's accessibility "certified" makes it seem like allowing litigation is not going to be produce meaningful results and could be easily abused.
This could easily be solved by requiring that the disabled person first contact the company and explain how the site is not accessible and if the company refuses to provide a solution then you can sue. The idea being that it never gets to the legal part because the company knows it is much cheaper to fix their website.
Perhaps rather than object to the court's decision it would be wiser to put energy towards updating the ADA to include standards for electronic access.