I think it is a complicated discussion. On one hand you want to make sure investors benefit the maximum, on the other hand, this blockchain is based on the social factor and most apps are too. So, without users which are going to consume the apps and games even though they invest relatively little into the actual STEEM POWER it is impossible to sustain the eco system and investors are going to lose interest too. Most people who are here today would be gone tomorrow if STEEM would stop giving them rewards which are actually worth something. And, making sure an SMT has an actual value, especially for smaller communities is going to be extremely difficult.
I think cutting the author rewards without having a sustainable model would be the death of STEEM.
On the long term more sustainable ways have to be found, using the advertisement rewards to sustain SMTs, backing SMTs with real use cases (payments for apps etc).
But, I think on the short and mid term this is not a discussion worth having. After SMTs arrive and after we saw the first SMTs which were able to sustain their own prices we should have this discussion.
Else, this will just lead to people leaving and not anyone coming.
As other people pointed out, there is so much more to people investing into a cryptocurrency than just the inflation it has and I believe the #1 thing we should be worried about is having real world use cases where people buy STEEM to spend it in the STEEM ecosystem (apps, games, etc) and the apps themselves invest part of this STEEM for RC.