The main thing that is required for SBD to be better is for STEEM to stop plummeting in value. It isn't necessarily the only thing, other tweaks might be needed and this was understood when some improvements were made in HF20 but we wanted to take a conservative approach and make one tweak at a time.
No crypto-backed stablecoin is possible if the crypto backing plummets too much and too fast. DAI would also fail (to remain stable) if ETH dropped like STEEM. BitUSD failed similarly several months ago.
As for the reward pool, I think the argument is basically that the system overall doesn't work in the sense that the high inflation contributes too much to the investment being unattractive, ultimately destroying the asset value, at which point the rewards become negligible anyway (which is what has happened). Your comments centered around differentiation, and that's certainly a valid perspective, but differentiating by being worse is hardly useful. Given such a choice it is better to be less differentiated and perhaps try to come up with other ways to stand out.