And you never see classical music afficionados argue whether, say, "Für Elise" is a masterpiece or worthless crap, no?
I don't see why discussion should be based on consensus - the discussion rather might, or should, lead us towards something more consensual. It is the spirit of the process. But indeed you are right - more people should look at the big picture, not only temporary aural pleasures. You won't see me spinning "Advent Parallax" or "Obscura" in the record player anytime soon, but I might take the time anyway to give them some promotion since they are inspirational pieces of work with value to people I trust.
It was only yesterday that I exhorted to some "elders" how beautiful it would be to agree on, say, top 30 albums of the last 30 years, but what I see happening in practice is that year by year our lists and reviews are differing more from each other. Consider "Belus", for example. This is not to say consensus is hopeless, but we probably need to approach it indirectly and express common courtesy and consideration.