It's not about hard-working or so much about originality it's about timeliness and popularity. Relatively few people will rush to read a novel just because it came out. Original novel writing will never be a good fit for Steem which gain it's value from ever changing trending page based on 7 day voting window. If on the other hand you are a known book author with a user-base and you publish your book chapters first on Steem or exclusively then I think the promotion initiative is worth rewarding relative to the amount and quality of viewership brought to the platform.
Want an other example:
If you manage to land a Steemit.com post to #1 rank of r/bitcoin or r/cryptocurrency , I'd vote your post to 80$ and will send you 500 SBD for the achievement.
If, on the other hand, you are a known Crypto blogger, you don't need steemit at all and should not get paid, right?