Of course anyone is free to do whatever they want on Steemit as there are not rules, but the community gets to decide what they like and if they don't like junk posts to get rewarded then they can flag them. No rule against that.

I don't like to here people saying 'everyone does ...' as it's patently not true. I manually curate what I vote on and I do read posts. The comments I get show that some people read mine. You obviously did :)

The curation crew put in a lot of effort finding bad posts and their rewards would make for a pretty poor hourly rate. The rewards scheme just goes some way to paying them back, but some would do it for nothing. If people are getting rewarded for voting up crap then we need some incentive for them to flag it. I sacrifice my SP to support this.

There are no absolutes. Steemit is not perfect as it's made of people and people will be greedy and/or selfish. We have to fight the winnable wars and leave the big cases to the whales. We can at least stop some spam minnows becoming bigger fish.