Right now we have bots that are powering down millions of vests a week and regaining the entire balance powered down simply by curating

I've seen this claim repeatedly made. It appears false. My power down rate is currently 20K/week. I'm making 3K/week with a combination of light botting and manual curation. Hive account@berniesanders is making 4K/week. Hive account@wang is apparently the most successful bot relative to SP and is making 2K/week while powering down 4K/week.

Seems there should be snopes page on this :)

More importantly though, voting for curation rewards is a competitive activity. There is always someone who is going to be the best at it. Looking at that one individual during one particular time window is not a good way to assess the effect of the mechanism across the overall system. This is no difference from balance in games. There might be a few excellent players with very high K/D ratios (imperfections of that metric noted), but that fact alone does not imply the game is unbalanced at all.

Also - writing is harder than curation, why should it be an equal split?

The rewards for reading are split among potentially hundreds or thousands of voters.