The Gemara in Sukka says that the reason why we make the Brochoh of "Al Netillas Lulov" and not "Al Netillas Esrog" is because the Lulav is taller. My question is why don't we make "Al Netillas Arbah Minim"? Especially because we learn out from Ul'kachtem that you're not Yotzei if you only took some?
It seems to me that Chazal did not institute "Al Netilas Arbah Minim" because it is too vague. A Berachah must be specific, and "Al Netilas Arbah Minim" contains no indication as to which species one is referring to.
I gleaned the following from a combination of the Me'iri and the Aruch la'Ner's comments on the Sugya. In fact, the Gemara initially thought that the Esrog might be the most important of the four species, because it is mentioned first in the Pasuk. But it concludes that the bundle containing the Lulav is more important because it incorporates the Hadasim and the Aravos, and we always go after the majority. Having said that, the Gemara goes on to give the Lulav precedence over the other two in the bunch, because it is the tallest.
And now that the Lulav is deemed the most important, we mention it in the Berachah, and it incorporates all the others.
The Me'iri adds that, in the event that one takes the four species one after the other, one recites the Berachah over each species independently.
Be'Virchas Kol Tuv
Eliezer Chrysler.