Its not a coincidence that ATR, RP and now SL have all come out with new websites, their old ones while perfectly usable on desktop had become outdated.
The designs of all 3 are now in keeping with the modern standard of responsive design which is the most widely accepted solution to catering for mobile and desktop users, the only other solution is to run 2 separate websites really. They use a responsive grid layout thats just a bunch of rows and columns which react to the size of the viewport.
If you resize your browser while on the new sites you will see the layout respond by displaying the mobile nav menu, changing text/image size and stacking columns to make it look good at whatever size. If you do the same on the old sites you will see the website disappear.
Mobile has long since taken over desktop in terms of number of users and internet traffic, and its only becoming more and more dominant. Everyone has to deal with it and our racing sites have actually been able to wait longer than most to conform because they are mainly for form study and no one wants to do that on a mobile. Can only assume now that even their traffic figures are starting to be dominated by mobile.
I think RP and SL have done a much better job than ATR which is too cluttered for my liking and I think most people will get used to them just fine.