@xaero1: I think each

I think each of the three you mention have different circumstances:

steem: Inflation is relatively high at 9.5%. But each year it is scheduled to decrease, with tale emission at 1%. So I don't think we can conclude too about 'too much supply'. Zcash for example has very high inflation but it's still been trending up. Moreover, steem absolutely needs some inflation (unlike bitcoin), for the payouts! The difficult question is what rate is best. But if steemit grows big I think there would surely be ways to generate profit too, even if that eventually means advertising. Facebook is free to use, but still generates great profits...because it can do this one way or another due to its network effect. Only difference with steem is that a high proportion of the payout goes directly to the content creators (which is the great innovation!) Anyway, I think it can sustain the inflation model easily provided it can accelerate its network effect (number of active users).
bitshares. Great tech., but I hold very little now (I used to hold a lot). Reason is that the shareholder gets very little / nothing out of holding. This could easily be fixed, but problem is that the original developer left and also due to the voting system. Not sure it can be fixed easily once the stakeholding proportions get stuck, and the devs have sold most of their stake to pay for development....this is why POW has advantages of POS in this regard. Logical thing for devs to do is leave and start a new project as Hive account@dan did (haha..). The way the issue could have been fixed would have been continued development and having tech where BTS holders get a share of the revenue....look at Lisk, Waves, Dash, Nem for examples where it pays to hold the tokens.
eos: this is a special case currently due to the ico schedule. This will constantly act as 'damping force' on price until we get nearer the end of the crowd sale period. When we do get nearer the end, I think the price could rocket up, if the tech can deliver what it promises. And unlike bitshares, there should be great value in holding the tokens as it should real value, because dapps will require it to get keep their smart contracts running.