I shouldn't have to pay the same price as someone who buys physical. I'm not paying for the disc, booklet (some hardly even come with one anyways), and box.
His argument is about the perceived and sustainable value of the product itself, not the COGS (cost of goods sold) you're referencing. The end-product is the piece of entertainment you are receiving and he is trying to argue that once you start to de-value that at lower price points it becomes increasingly difficult to maintain the overall premium price you need to sustain to reach profitability. Also it becomes increasingly difficult to "raise" it again (which often triggers contraction, or forces alt rev models such as IAP on mobile).
Big games these days are budgeted years in advance and built on an existing revenue model of $60 (then factoring in depreciation). If the market shifts too rapidly toward a lower price point - let's say his case of $22 - those products that release that were budgeted in a different monetization environment are doomed to lose money, as there is no real "lift in sales" yet to make up for the revenue loss from consumers who wouldn't spend the $60 mostly due to limitations in the channel (mom is going to gift you the game for the holidays if she can't find it in stores because it's only on PSN as an example). Consoles aren't at a big enough install base and digital attach is still between 20-30%... So the money you lose on that 40$ price drop isn't made up by volume of additional consumers you'd get digitally yet.
So then you'd have to cut budgets to return to break even point which likely means layoffs and lower quality games than what the market is demanding, which in turn could have the affect of no longer growing the market as you wouldn't be able to take as many risks if the big returns aren't there to re-invest in new IP or smaller, non-blockbuster titles.
These pricing rebalances will happen, but I get the impression he is saying from his perspective it needs to transition slowly and be well managed in order to account for different pricing models to maintain the perceived value of the game, despite how quickly the technology and COGS change.
That's why you see such a big digital push for ARPU and microtransactions and all that - helps stabilizing pricing disparity, can bring the $22 users closer to price parity and gives the remaining $60 loyalists opportunity to invest more in the games they really love and want to continue to play (and are probably in return buying fewer games because they are more invested in the few $60+ games they do buy retail).
Anyway there's no Right or Wrong, just depends what house your chair sits. Industries so dependent on technology often have growing pains during tech transitions since their P&L is so closely tied to it.