It's either require a small investment to participate in any meaningful manner or put up with endless spam. People are more likely to invest energy and time (make an attempt to offer value) if they're required to invest a little money.
Without anything to lose, there are essentially no risks that come with spamming the network. With something to lose, that money can go to waste if you get yourself flagged into a negative rep, making it less likely to happen.
Every action on the platform requires bw
Follow, unfollow, Comment, vote, everything
This isnt about spaming. Its about user experience and capitalism (if you want people to invest before they can enjoy steemit in its full potential)
It is a big problem to fight with spam. Above all because it hurts people who work hard making quality content and due to the lack of enough whales to support them, they go unnoticed. I encourage them to help create more whales that support to people and fight spam. You are doing a great job producing reports and useful content for everyone. Thanks for watching and making Steemit a healthy community.