I didn't read the comment as a troll or any of what you said about the tone. It seemed to me to be an accurate account of what has happened before: Bitcoin bank/exchange gets hacked or has other issues, and people lose confidence. This is empirical. To deny what 30 seconds of Googling and a review on BitcoinCharts.com confirms speaks to your "evident knowledge of the Bitcoin ecosystem".
You are right that you can store Bitcoins anywhere, and aren't restricted to banks/exchanges. However, this protects only the coins themselves, not the value. As things stand today, Bitcoins are only as valuable as you can trade them for fiat currency, or for products/services that continue to accept fiat currency. Where and how you store them has no impact on what the market is bearing as value for Bitcoins, and faith in the banks/exchanges plays a huge role (though there are other factors as well) in the market value.
You are right that you can store Bitcoins anywhere, and aren't restricted to banks/exchanges. However, this protects only the coins themselves, not the value. As things stand today, Bitcoins are only as valuable as you can trade them for fiat currency, or for products/services that continue to accept fiat currency. Where and how you store them has no impact on what the market is bearing as value for Bitcoins, and faith in the banks/exchanges plays a huge role (though there are other factors as well) in the market value.