'protect the reward pool' is a PR friendly version of 'direct the reward pool elsewhere'. the gist of the stated intent by the biggest downvoters is generally in alignment with the idea of 'protecting the reward pool' or alternatively 'looking out for the little guy' - whereas what many people are pointing out here seems just as likely or more likely, given the self interest of investors, that the downvoting is self interest motivated.
Much of this ongoing discussion seems to involve different people accusing each other of being self interested, which is both valid and also a bit weak considering that Hive is an investment vehicle, of sorts. In my perception there is a real gap, though, between the perception of people who invest in Hive mainly as a way of supporting free speech on the internet and people who invest just to make money. It is unusual to have an investment opportunity that so directly effects social interactions on a daily basis - in some ways it isn't healthy, but on the other hand the alternatives are often far less healthy.
We COULD actually cultivate health and social cohesion through the voting on Hive and that is part of what I found so exciting about Steem early on - it is an opportunity for people to understand harmony and interpersonal relations in a way that spurs personal/societal growth. However, inevitably, the imbalance of the world will emerge here too - currently perhaps easiest identified by the whales who arbitrarily choose to nuke entire accounts without explanation or community support.