This is a purely subjective term and depends largely upon individual perceptions. As I see it, alpha binoculars (whether or not you like the term) are defined by those binoculars produced by Leica, Nikon, Swarovski, and Zeiss that entered the market in the last few years at a price above $2,000 US. I would bend that for the Swarovski SLC series. I also see a terrific tendency to automatically associate those with greatness. As somebody here has said more than once, good marketing need not be truthful, only believed. Yes it helps that those are terrific instruments.
As to who is qualified to make the determination, as far as I am concerned beauty lies in the eye of the beholder, another appearance of human perceptions. I have long held the opinion that the users satisfaction with a binocular lies solely in the ability of the binocular being used to shut off those little voices whispering in ones ear, that there has to be something better, and that since there is I will see it. That singing of little voices may not be quelled until the user gets to the alpha (flagship...whatever adjective you care to use). When the viewer realizes there is no more to be spent, those little voices may well go away. At that point the user just uses the binocular and the class of the glass gets the credit. At another point on the spectrum a less expensive glass may well quell the voices. Available disposable income and perceptions of personal spending preferences play a role here too. Nothing wrong with either, it seems to me to just be human nature.
Cell phones have a site where all of the flagship models are torn apart, piece by piece. The cost of the parts are determined, the phones are evaluated on the quality of the part and the level of construction, and given a repair score. Unless binoculars get a site like that nobody will have the ability to make that sort of determination. Again, beauty lies in the eye of the beholder. Even a great name on a lesser glass may well confer status on the lesser glass.
As to not being an optical engineer, does that mean you have to be a automotive engineer to evaluate an automobile to see whether or not it suits you? I make no pretensions about being any sort of a optical expert. I am however capable of forming and stating my opinions on various instruments. Win some loose some. Blessed be the name of the game.
