No, the fact that the product is not "physical" doesn't matter. Both took resources to produce, and both provided "value for money" over the year+ that I had them before they went on sale.
In fact, my analogy works perfectly for the situation as you describe it. I paid [x] for my machine with 8GB of RAM. Now someone can pay less-than-x and that includes 16GB of RAM. You seem to be saying that the vendor should offer me a discount if I want to purchase the additional 8GB because I paid more originally than the person buying today. I just don't but it. (Pun intended.) And that's what I tell anyone who feels "It's not fair". Then don't buy it.
And the Steam comparison is totally irrelevant. No one is arguing that EA can't offer such a bundle/discount/deal.
I'm simply refuting the argument that they must/should.
Well, if you wanted to buy only RAM to increase the performance of your computer, I'd expect it to have a similar price to what some random guy would pay now for it in a new computer...
I usually build my own rigs, and buying the parts is always cheaper than buying the build even with a discount.
Also, you say that those who paid for the game in the past year have to wait for the DLCs to go on sale if they don't like the price, while new gamers have a discount on those DLCs. Except that they may have already waited for the DLC to go on sale, and they now have to wait longer than newcomers.
With your analogy, if I bought a computer last year, but chose not to take a SSD, waiting for the prices to drop, if I see people buying computers with cheap SSDs now, I'd expect to be able to find a cheap SSD myself rather than wait several months (again).
So if you consider the DLCs by themselves, gamers who own the game have to wait longer than newcomers for a drop in price.