I don't know if your ideas of what you want to see is better or not, but I certainly wouldn't try to challenge you on figuring out a good solution (ie you and asgarth have earned much respect by me and others).
I do however think you are wrong about the value of the rental system you have developed. I don't think its failed at all, in fact I would argue without it the game would've never progressed to the point where it is today (on the good progression side of things). I know many people rely on rentals and I think you will hear an outcry when its removed. That's ok since as you said there wasn't much money in it for you, but to me its a shame that @aggroed and @yabapmatt didn't figure out how to support you guys a little extra for the value the rental system brought to the game.
In my opinion the game will suffer in the short run as a result of it being stopped.
Having said that, it is what it is and I look forward to what you come out with to replace it. And maybe next time the devs will appreciate the value it brings more. (ps... its a shame to have to go through these ups and downs when the value is so obvious in my opinion, but in the long run I think we will get there and thanks for all you both do!!!)