Because that’s the logical fallacy of Denying the Antecedent . If “it’s raining” then “the sidewalk is wet”. Knowing that it’s raining tells us something about the sidewalk, it’s not dry, it’s wet. And knowing the sidewalk is dry tells us something, it can’t be raining (because if it was, the sidewalk would be wet).
But knowing “it is not raining” doesn’t tell us about the sidewalk (it could be dry, it could be wet, maybe it rained earlier, maybe a dog peed on it). And similarly knowing the sidewalk is wet doesn’t tell us anything about the rain.
So even if “mo money causes mo problems” all that tells us is that someone with mo money will not be problem free. People with no money might also have mo problems, the syllogism doesn’t tell us about that.
Because that’s the logical fallacy of Denying the Antecedent . If “it’s raining” then “the sidewalk is wet”. Knowing that it’s raining tells us something about the sidewalk, it’s not dry, it’s wet. And knowing the sidewalk is dry tells us something, it can’t be raining (because if it was, the sidewalk would be wet).
But knowing “it is not raining” doesn’t tell us about the sidewalk (it could be dry, it could be wet, maybe it rained earlier, maybe a dog peed on it). And similarly knowing the sidewalk is wet doesn’t tell us anything about the rain.
So even if “mo money causes mo problems” all that tells us is that someone with mo money will not be problem free. People with no money might also have mo problems, the syllogism doesn’t tell us about that.