Nearly all manufacturers do not advertise/exhibit their product measurements? Why?

Just tonight, I was attempting to find out a few basic answers for a driver. The translation was so poor, that I will just look elsewhere. No need to bother those who cannot simply provide basic specs. To be clear, the specs were provided in such a way that you had to know that the typos actually meant watts instead of ohms, for example. After a long list of errors, i had to ask myself why I bother. There is a mountain of other choices to narrow down for the design to start with.

@ebm 

Because nobody cares much.

And that's the way the manufacturers and the vested interests on this forum want this situation to remain. 

They are going all out to discredit outfits which conduct careful measurements, its pretty obvious even to blind freddy.

The reason is likely based on manufacturer- ultimately because the customer that buys there stuff doesn’t care if they aren’t publishing measurements. 
 

People often make emotional decisions then justify with facts. Rarely the other way around. Think about your significant other or best friend- there qualities were something you learn over time and something about them impressed you enough to follow up from your first discussion. 

@overthemoon

The reason is likely based on manufacturer- ultimately because the customer that buys there stuff doesn’t care if they aren’t publishing measurements.

This is also quite correct and you share a truth.

What is missing from this truth is the analysis that it is the marginal customer, the one who questions the price, quality, whatever, and ends up buying it, is the one who determines what everyone else who don’t care, get.

Without going into handwaving, this is true of any freely traded commodity or service.  Some people call it supply and demand.  Do they explain exactly what that means?

"Just listen to it" sounds good, but those of us who were around when amplifier power "specifications" were mostly a figment of the manufacturer's imagination should appreciate today's more accurate power reporting requirements.  Is there still a little monkey business going on, maybe some, like reporting half of the 4 ohm power measurement as the 8 ohm power output (when it is really higher) to make it look like the amplifier power doubles into 4 ohms, or maybe the actual distortion at the reported output or reporting results at 1K Hz instead of from 20-20K Hz, but mostly the reported values are much more reliable than in the 1970's.

In the case of speakers, I don't know why any potential speaker buyer wouldn't first look at efficiency and impedance specifications, just to make sure the speakers are likely to mate well with their amplifier.  DAC output voltage is another useful specification/measurement when determining the gain (or not) needed from the partnering preamp.  Output/input impedances for source components, preamps, and amplifiers are nice to have in order to head off potential component mis-matches that can lead to rolled off or uninspiring sound.