You're comparing apples to oranges
The game is like the view port in your modelling app. You can use the viewport for render and you will get same 60fps speeds.
There is no reason why you can not get realtime graphics that are very good out of modelling software like Maya or 3DS Max. Results that are par with many games. They have viewport shaders just like games do. There is also a viewport rendering option that chunks frames to disk as fast as it allows (I've done full HD renders at 30 fps from Maya). All you have to do is stop using the provided software raytracers.
There are some differences though. The primary difference is that you as a user do not optimize stuff as much as game developers do (optimization is using all the tricks in the book). Second your animation primitives work on the CPU because you need the flexibility. In games one can afford to do optimizations. All in all you pay for not having a programming team next to you.
Many of the things may in fact have been precomputed, so they aren't so much faster just better organized. Baking your indirect illumination will beat non baked results every day.
Why are the raytracers slower?
They aren't*, one just tends to do more work on a ray tracer because its easy. Feature by feature they aren't much slower in computation cycles. For example theres no need for a ray tracer to cast secondary rays (life reflections in that case the ray tracer will cull geometry away, or not even load it, in fact mental ray does just that). Its just usually done because it trivial to do so and that's the clear advantage of ray tracers. You can even configure them to run on the CPU in some cases. They are just optimized for different things:
Emitting data to disk, not just frames but all data. Something which would break most games speediness instantly.
Working on general hardware. The GPU is much faster for certain things once you optimize for the GPU. But it does not work for all loads, in fact a Intel CPU is faster at computing in general than the GPU. The GPU is just massively parallel which the CPU is not. The architecture wins if you can stay in the GPU and minimize transfer and optimize for the GPU architecture.
So you pay for flexibility and ease of use. But yes ill admit both Maya and Max suffer from extreme old age. So they could be faster.
TL;DR The difference is mostly in optimization (read lots of tricks) and available external resources.
PS: There is a misconception that this is because it is more physically correct. It certainly can be but the ray tracer is not inherently more physically correct than your average game or any other computation. In fact many games use really good models while quite many modelers do not.
* See http://www.graphics.cornell.edu/~bjw/mca.pdf
