This to me seems a major problem. But, what I am not clear on, is whether this means that the average value of a transaction has fallen, or if less transactions are being made. If the number of transactions has increased, but the average BTC has fallen, that would seem a good thing, -BTC are being increasingly divided and spent; but if the adjusted value (say in dollars) of BTC transaction has fallen, then that would be bad, -spending is falling.
IMHO, a Bitcoin that was easier to mine might have more success.