I think it also depends on the type of object and the scene set up. some rendering are suited for studio set up, some are for still image (no robust motion blur set up), some are good at handling Giga size data, some are perfect for big texture displacement, some supports PTEX, and some are highly customized so that you can write your own shaders. so the choice is also tied to your profession.
in my opinion, if you just started to learn rendering, then pick the one that offers the best support for your job. for example, most archviz choose Vray because arch-related 3D model you can purchase (furniture, street signage, 3D plants, pavement, etc) shipped with Vray Material. while film production tends to pick blockbuster-level renderer like Pixar’sRenderman or Arnold (though Ive seen few production companies uses Vray too). and I ve seen Maxwell used in Commercial clip.
as comparison, 3dsmax and Maya comes FREE with Mental Ray, which is actually a renderer engine that is comparable to Pixar’sRenderman. and I have been waiting for Rhino to have such “bonus” feature