Yeah, Ryleh and I never banded together to take it down. I always kept thinking Ryleh would, what with being the astral king, but no.
I believe Nature's Bounty gives a max of 3x income, so yes, they were pulling down a total of 9x normal income. I'm not sure I would mod it out though; we could have taken it down if we had cooperated more, and I don't know that it is any worse than any of the other big end game globals. In the other high resource game I am playing I'm waiting to see who casts Nature's Bounty first, and exactly how much stompage they receive.