We need to focus on creating demand via organic growth, decreasing the supply doesn't do that. Removing the reward pool from the equation is a major change that would turn the token economics on it's head, at least in the mid term I don't think it's viable. If SMTs are succesful then we can start considering it.

Think about it this way, if we reduce the inflation to 2% at the current prices the witnesses will need to have half of it or 1% in order to have adequate compensation. By witnesses I mean all of them not just the top 20. That leaves another 1% for stakeholders and the SPS.

Basically we would have the current distribution locked since the only way to acquire steem would be to buy it.

EDIT: Maybe accelerating the rate at which the inflation decreases would be a better option.