The system is really complex, and even people that are here since the start still learn new things everyday. The curation is, for me, fair, as it rewards you for upvoting other people posts (hence reading, interacting, finding good content, etc.). In the case of the bid-bots it's different, as they profit from this curation system without bringing the "good things" (interactions, as they're are automated bot paid for voting) that are expected from this system.

And yes for the little upvotes, that's unfair as Steem is 100% based on stake (your Steem Power, hence your wealth) and they should be other criterias taken into account (interaction for example, engagement in the community, etc.).