Why don't speaker mfg list amps and associated equip they use to " voice " their sound?

It could be limiting and it also means you are endorsing another brand that you may or may not have a relationship with.  

I do offer guidance and examples of brands that work well with my speakers.  Obviously I am going to be biased towards brands I carry but it does help with inference.  The unfortunate part though is that it is reflective of my taste. Looking at many systems out there, lots of people like extremely bright setups so I may be doing myself and injustice.