What should be mandatory in every professional published review-

Where's the OP gone? What should every poster here, if they were professional, do? There's a myriad of preferences and likes/dislikes, just as in any marketplace, but @mikelavigne summed it up very nicely. You choose to read what you are looking for, since we don't have journalist and publications police... thankfully. Maybe another source can take on the role of industry critic's critic... mind you the marketplace here and elsewhere seems to do this very well already.

A few other things should be mandatory: What does the item smell like? How many total parts does it have? Can it survive being attacked by gorillas? Does the warranty cover excessive rust? How long can it float? Can its lights lights trigger a seizure? Can you sit on it? What temperature does it reach when disconnected?   Without these things being addressed you just can't take a review seriously.

How long can it float? What do you mean? In mercury? Seawater? Molten lava? 

Specifications are technical. Where's Amir when you need him?

snapsc- fully agreed & of course what ancillary equipment was used & what other equipment was tried w/ the reviewed piece.  Stereophile is good w/ this, Absolute Sound often not.