Speculative "investment" is not relevant to sustaining the valuation of the steem token (not in the long run). We need more businesses that take advantage of the inherent properties of the blockchain as a data storage unit and the fact that it's super fast and feeless. Steemmonsters is an example. You need to stake steem in order to have enough resource credits to perform actions on the blockchain. If enough businesses are built that leverage these properties then the supply will dry up and the price will follow.