The point being made was that it is a desktop-class machine. Generally, laptops have always been convenience and portability, and desktops have had power and price point.
Obviously there are exceptions to any rule, but in this case, the display is actually better than any desktop I've seen, and the SSD and CPU/GPU give it all the power necessary for 95% of users. The price point is definitely high, but otherwise it seems best of both worlds.
You've always been able to get a laptop that was as good as the desktops of 2-3 years ago, and never one that's as good as the current ones. Saying "desktop-class" is a nonsense; this is no different from previous efforts.
Now, if you're saying we've reached the point where the extra CPU etc. of a desktop are not worth it for most users, then I agree with you. But again that's nothing specific to the macbook air; any modern laptop will have the same properties.
Compared to a high-end desktop which has barely seen updates since 2010, and includes a GPU released in 2009, sure.