Some of my favorites are from the later generations as well, but I would sacrifice them to get rid of the stupid 200+ other Pokemon that those generations brought (Corphish is pointless, we already have Krabby, Taillow and Starly are pointless we already have Pidgey, etc.).
Basically, his point was that the later generations of Pokemon weren't really churning out new Pokemon for the most part, as there is a "Caterpie" and a "Pidgey" and an "Oddish", etc. in each of the successive generations. There's no need for more than one of the same Pokemon, which is essentially what is happening in the later gens.
I'd be all for keeping the more original ones like Absol, but all of the duplicates need to be cut. And the easiest/quickest way of doing that is to just scale back to the original 151, which is what he did.
Also, Swampert is hideous. :lol
EDIT: Zilch, he was deciding whether they were pointless or not based on their usefulness in competitive battling. Farfetch'd is completely pointless in that regard.