I agree with you that older cards need MORE gameplay utility, and should NOT be destined to be locked away on a plot of land. I also believe part of the problem is pricing these assets too high out of the shop. The market is telling us this is not what these assets are worth.
We do get stuck in a loop, where we need new players to make asset prices rise, but decreasing asset prices (because they are sold at too high a price point) keep new players away.
We have to discover our niche for pricing and marketing. We have not figured that part out yet, and it's a vital piece of the puzzle!