>Are you suggesting he provides a bigger reward for work as time goes on, thereby providing more currency later in the piece?

Yes.

The minting design Satoshi choose merely granted a few users the majority of the supply for the least amount of work. They can then horde and hope to sell at a profit to late adopters.

>That would be counter-intuitive to the idea of bitcoin as a fixed store of wealth

No, the total supply remains the same. Distribution and production is the issue. The linear curve should align to match the energy and work input, assuming that is representative of additional users joining the network.

Fixed store of wealth is even more difficult to achieve, as users must trust the design to be desirable.