A friend once tossed a $100 bill from her birthday into
    the wood stove with birthday wrapping paper. There was no 
    expectation this form of currency could recover access by 
    negligence, fraud, theft, acts of god, or otherwise, yet 
    she was thrilled to mass-adopt that $100 until it turned 
    into ash.

Remove the negligence item and fraud and theft are still there. Banks and other regular institutions have remedies for these and they are an "improvement" for most users in this area.

Put that together with the fact that it is far and away easier to lose your cryptocoin holdings than it is to lose cash or money in your bank account and a cryptocoin is in most ways a step backward for consumers. They benefits they tout (Easier to send money to someone else, Proof against government meddling) sound good but the second is why it's a step backward for most people and the first is hampered by the combination long transaction times and the volatility of the coins value.

Is it possible that these will all get remedied? Sure. But until you remedy them most people shouldn't be using a cryptocoin unless they can afford to lose what they put in there.