It's not about comparing quality, it's about comparing consistency. Brands want their blends to be consistent from year to year. So every year they might create hundreds or thousands of different combinations of the specific teas they've acquired, until they find one that tastes as similar as possible to the blend they had last year.
Also, green tea is just fine at boiling, if it isn't of poor quality :)
It means something, which in this case means "taste is individual". I prefer to take the advice of my green tea supplier, who tells me to use 75°C water for brewing my tea. Using other advice is up to the user. Not my monkeys, not my circus.
Also, green tea is just fine at boiling, if it isn't of poor quality :)