Yes he is correct - you can test out the mobile version in a web browser at
http://mf.sex141.com/iphone.html
This was released in 2011 when smartphones were a lot less smart, and many features were stripped out. Not only can you not rate, but you cannot see any ratings, so a lot of content is missing.
Actually I loaded the mobile version up for the first time now to see what it looked like. I use my smart phone probably for 60% of my online time, but always use the regular site. Screens have got a lot bigger in the past few years.