Here’s the reason I see it as money:
The water can only give. The plants give nothing back.
So the watering can gives and gives and gives and gives.
The watering can gets nothing in return.
There is no benefit to the watering can. It is a portrayal of selflessness that can make the receiver seem greedy in this metaphor.
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A coach as a watering can would be good.
But a marriage or other kind of presumably equal partnership has too much of an imbalance. Even the father/son cartoon I show has an implication that the father will be gone at the end and the son continue, which is acceptable.
But an empty husband and a wife full of his nourishment doesn’t seem to be a good kind of imbalance.
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