Blender's main focus has been around providing a strong 3D design surface / editor with support for a wide array of uses (everything from rendering static images and movies through to game creation).
POV-Ray, on the other hand, has always had the singular goal of providing a solid ray tracer. Whilst a text editor is usually supplied and 3rd party 3D editors are available, the core engine functionality (exposed via the language) has been the focus of the development effort.
It's also worth noting that while Blender still enjoys an active developer community, POV-Ray's small but dedicated development effort seems to have all but stalled for at least a few years now.
If you're looking for contemporary photorealistic renderer, then POV-Ray may not be the best choice... but if you're after an interesting little exploration into quite a powerful little ray tracer that can be controlled relatively easily by hand written scripts, then POV-Ray can be a lot of fun.