This isn't really surprising at all, if you understand time preference, which obviously you do not. The revenue stream is only infinite if you defer consumption forever, and no mortal being can rationally be willing to wait forever. Eventually you and everyone you have ever cared about will be dead, and beyond caring about any further revenues. Any production past that point might as well not exist.
Consider this: under what circumstances would eating the goose be valued more highly than twenty years worth of golden eggs? Starvation, perhaps? Would it really makes sense to preserve an unending supply of golden eggs at the expense of starving in the present?
I clearly specified the goose lays eggs in perpetuity, no deferring of consumption is required to enjoy the utility of the eggs which is measured at $1000 dollars a year. The point about eating the goose is exactly to show that under interest we would be compelled to make choices that curtail future productivity, obvious being under duress such as starvation would compel us to make short-term choices, so interest forces us to act AS IF we were under duress at all times.
Put as simply as I can manage, you aren't qualified to tell anyone how much they should value future goods relative to present goods, any more than you are qualified to dictate any other form of economic preference to others, and yet that is exactly what you are trying to do with demurrage. You yourself act in a manner which is consistent with having a positive time preference--since you haven't starved yet, you clearly do not always choose to defer consumption--and yet you fail to perceive or understand this unchangeable fact of mortal existence and call it "irrational".
You seem to be stuck in this notion that without time-preference we would never act and this comes from our mortal nature and knowledge of that nature. This ignores the marginal utility of consumption within a time period, we know that the first bit of consumption has the highest utility and the next bit is reduced, so hunger for example is an ongoing need that will arise anew every day even after a high levels of satisfaction the day before. If I want to maximize my total utility over a finite time period with a finite supply of food I would amortize the consumption over the period to keep my total hunger to a minimum. I would not need to have any preference for satisfying immediate hunger more then future hunger to do this, just a preference for satisfying hunger generally. Any ongoing need that people have that relate to comfort or pleasure follow the same pattern, we defer present consumption only if it offers the promise of maximizing total utility over time.
Furthermore I can refute that knowledge of mortality and finite time-horizons give rise to a preference for immediate gratification, exactly the opposite is the pattern we see in real human behavior. Individuals unaware of their mortality consistently show the greatest desire for immediate gratification such as little children. As people mature and become more aware of mortality their decision making consistently becomes more focused on the future as they make decisions to maximize utility over the finite remainder of their lives.
Compound interest doesn't reduce your return in the slightest. It just means that there was a better alternative. Put another way, you could have put $7 in the bank at 5% interest (i.e. into other investments earning 5% annual ROI, as opposed to the tree at a mere 2.3%), and gotten the same $1000 in 100 years for your grandchild, and still had $93 left over in the present to spend or invest as you choose.
Your making the classic Austrian error of assuming that high interest rates cause high productivity investment opportunities to just appear such that all investment flows into productive investments rather then diminishing the total investment activity. This is patently absurd, interest rates simply cut off the lowest rung of productive investments, it dose not change the material productivity of any activity, only its profitability. The tree investment indeed did have a 2.3% Internal rate of return but that rate dose not change based on the prevailing interest rate because internal rate of return calculus is explicitly to determine at what interest rate is a venture break-even. The 5% returning investment still exists when interest is 0% and it still has a 5% internal rate of return, but with 0% interest its very attractive rather then just being barely breaking-even.
Entrepreneurs will always invest from best-to-worst. The best investments with highest Internal rate of return get funded and then the slightly less savvy entrepreneurs take the next slice and the next and so on until people decide the remaining investment opportunists are unprofitable. If the investment activity hits the floor created by interest rates it dose not bounce off and go back into the high return investments because they are already funded. Would be investors simply cease to be investors and are left with no choice but to consume their capitol be it monetary or physical in a non investment activity or watch it decay before their eyes.