There's a tendency to latch onto really interesting new concepts and use them indiscriminately. Then comes the recoil back towards reality.
Responsive is less cool when it has been done to death for no apparent reason. Flat design seems excessive when everyone just flattens turds. Even things in other mediums — when audio panning was invented, movies would use them in excess for no reason. The same thing happened with 3D movies.
There's always the big irrational spike of enthusiasm.
Responsive design is not just about mobile devices; viewing a Web site on my Cinema Display or on my Macbook Air is not the same thing. I understand that designing a fixed layout would use less design/development resources, but I hardly see the benefit from a user perspective. It is one thing to ditch responsive Web design to meet business goals, but trying to make misguided assumptions to justify it from a user point of view is a whole other thing.
It's good they looked at their stats, but without further insight into their actual design and development process, this seems misguided. The diversity of screen sizes will only get greater as we move into the future, and you also never know who's in that 2% of people - they might be your best next customers! Building flexibly and properly responsive is a good investment for the future. That being said, maybe they will change it all again next year, who knows.
I have to mention my own web design app, Edit Room, which makes creating responsive, multi-screen web layouts as easy as dragging things around on-screen. If you start your design work in the browser, you save so much time that lets you go that extra 10% on a design. That gives you the time you need to make your designs work everywhere.
Finally - there have been a ton of articles questioning the validity of responsive design but all of them were based on hypotheticals: - what if we don't need it - what if the experience is worse than a split mobile / desktop site, etc
At least here they use actual data to explain the decision which is completely sound to me.
At least they took the time to think through if it was right for them. Although, it seems like they took a desktop first approach which is kind of backwards and might have led to some of their issues.
But all in all, with 2% mobile use, it seems like they made the right choice for now.