I think he’s saying that the benefits of them would be so miniscule that they wouldn’t make much of a difference. It’s hard to say what other stats like Crit and Direct Hit scale like in PotD/HoH, since you cannot look at your proper character menu in there, but if they return to baseline and scale in fixed intervals with the Aetherpool Arm/Armor, then +8% Crit may not be all to big of a difference damage-wise. The only ones that would have a noticeable benefit would be the extra HP from the extra VIT food gives you. But even that would not be terribly significant; could mean the difference between living and dying for anything that isn’t a one-shot, though.
That being said, I don’t see a reason to not use cheap food in there for extra Vitality; I just don’t think it has a great effect on other substats to make it something necessary.