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

After my Audio Science Review review forum, it became apparent that nearly the only way one can determine the measurements of an audio product is wait for a review on line or in a publication.  Most equipment is never reviewed or is given a subjective analysis rather than a measurement oriented review.  One would think that manufacturers used tests and measurements to design and construct their products. 

Manufacturers routinely give the performance characteristics of their products as Specifications.  Those are not test measurements.

I searched the Revel speaker site for measurements of any of their speakers and could not find any.  Revels are universally lauded for their exceptional reviewed measurements.  Lack of published manufacturer measurements is true for nearly every speaker manufacturer I've searched for on line, perhaps several hundred.   Same is true for amps, pre-amps, DACs, transports, turntables, well you get the picture.  Do they have something to hide?   I doubt the good quality products have anything to hide but poor quality products do.  

ASR prides itself in providing "true" measurements that will aid in purchase decisions.   Why don't the manufacturers provide these measurements so that reviewers can test if they are truthful or not?

Then there are the cables and tweaks for which I suspect that there are inadequate tests available to measure sonically perceived differences but which objectivists believe don't exist or are "snake oil."  

Well, please chime in if you have some illuminating thoughts on the subject.   

I would have loved to see manufacturers measurements on my equipment and especially those that I rejected.