I agree, you are correct on that playing around the abilities can be done, but there is still the fact that if you get some boosters of any newer set, you will need a lot more cards of the same set to build a succesful deck with those new cards.
I had the feeling that with older sets, the synergy between old and new cards was much better, allowing you to easily blend in your new cards in your older decks. But I guess that is not a financially solid basis for any company distributing CCGs...