We didn't try EIP without the curve because our best available analysis and the consensus view of stakeholders, witnesses, and the developers is that it wouldn't work. (This does not mean 100% that it wouldn't work. but we have only a certain number and frequency of shots at this so we have to just use our best judgment to choose shots and take them.)

The limited amount of free voting power and the fact that there isn't any known way to compensate downvoters means that relying too much on downvoters doing a lot of hard work is a very dodgy proposition. The more obvious, more concentrated milking and abuse in Trending and voting circles is one thing. Digging through tens of thousands (and potentially more than that if incentives change) of tiny milking payouts is something else. The curve takes the place of someone needing to comb through and enormous number of low-payout posts and individually decide which are milking and which are not. That it is a broad brush is the unintended side effect, but, unfortunately, we simply don't know of a better way.

As far as giving low-earning voters blanket free upvotes simply for existing, I'm not in generally favor of that. It falls within the scope of curation to decide what rewards are appropriate and to a large extent that is independent of whatever rewards might have been previously (under a very broken system that, broadly speaking, was widely viewed by stakeholders, witnesses, and developers as a failure that was contributing to Steem's decline and not its success, though this does not mean that every single payout under the previous system was bad; that certainly was not the case).

As I said earlier, increased curation is still ramping up and will likely take some time. Most probably some low earning users will be picked up by increased curation (including increased votes that may be given because rewards are considered deserved by the curators and the curve requires it) and some will not, which is how this is supposed to work.