Funnily enough, my grandparents were telling me about how they were suspicious of debit/credit cards when they first started. Now of course, they feel very comfortable using them. Not directly comparable with bitcoin, but interesting in the sense that it was a significant paradigm shift in the way money was spent - initially met with skepticism, but eventually it caught on.
Isn't the exposure making people less likely to trade? No-one wants to spend bitcoins because they're afraid they'll grow in value and they will have wasted money.