These are perfecly valid questions.
There are several reasons why I consider fast ray tracing interesting:
First of all, ray tracing can do things that a rasterizer can't do, e.g real recursive reflections & refraction of arbitrary surfaces. And, it does these 'effects' in a very natural manner, as it simulates natural light transport. A ray tracer is therefore relatively simple: Physical effects don't need to be hacked, they can be simulated. A 3D engine based on hardware or software rasterizing on the other hand is usually a mixed bag of various tricks, and some things remain difficult to approximate correctly. Also, visibility determination comes for free: A ray tracer already detects what's visible and what not, no need for special constructs.
Secondly, ray tracing scales much better with scene complexity. I use a BSP (the kd-tree variant) for spatial subdivision. Doubling the number of polygons adds a level to the tree. Going from 512 to 1024 triangles therefore has only a 10% impact on performance. This can be taken to extremes: I can render a model of several million triangles with accurate self-shadowing and illumination at several frames per second.
Third, ray tracing scales almost perfectly with processing power. Individual rays are completely independent of each other (well, there's the cache of course...), and so parts of the screen can be rendered by different threads without complex constructs. Also, rendering using multiple machines on a network is quite easy to do. Performance scales linearly with the number of available processors.
And finally, it's challenging. Ray tracing is easy to grasp at first, but hard to get (really) fast. I am using SIMD to trace 4 rays in parallel, a kd-tree build with the latest insights (there are people who write 200+ pages on this problem), and the code is optimized to the bone: Things like caching, hot and cold data, const correctness and compiler hints really do matter, more than you perhaps think. It's cool to see that in real life.
About room for improvement: There is room for improvement. What I currently consider the 'King of the Hill' is a program that serves as a plug-in for the released Q2 source code. It completely replaces the Q2 rasterizer by ray tracing; it gathers the scene polygons, builds a kd-tree and renders them, with reflections and all. Resolution is 512x384, frame rate varies between 5 and 10fps, on a 1.7Ghz laptop like mine. That's just hardcore.
Some German guys experimented with ray tracing hardware. They built a 90Mhz prototype FPGA chip that traces rays at double the rate I can do on my CPU right now. The chip uses only a fraction of the transistors that modern accelerators use. If NVidia would build a chip that does that at nowadays speeds, and places it in parallel to match todays transistor counts, we would have a dream machine.
So there's some potential. But frankly, for me as a coder it's just the ultimate optimization / theory project. You should try it.