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

When your goal is to sell stuff it makes no sense to specify constraints.   

Agree with onhwy61, it would cause some users of electronics different from those used to voice the speakers to dismiss those speakers without hearing them.

Vandersteen, Audio Note, ATC, several *do* make amp components.

For many reasons (including envy from all the other manufacturers) it would be a PR nightmare for, say, Focal or B&W or Wilson to name names.

Why stop there? Why not have them list all the cones and footers and shelves, room dimensions and acoustic treatments, speaker locations and listening positions, on a spreadsheet showing day to day so we know exactly what was the setup when each capacitor and wire and screw and grill was tested? Don't we need to know these things? What design software was used and with what settings? What microphone and who did those response measurements anyway? 

Probably the whole thing should be on video, to go along with the 50 thousand pages of equipment setup notifications. 

Or we could just listen and see how they sound.

Hmmmm, dunno. Tough call.

It's a Show and that is what they do . Show and make sales.