I intend to take my bitcoins to the grave, or will them to my descendants.
The fact is, even if bitcoins "fail" (whatever that means,) they'll still be around. And considering what they are, and how they operate, they will still have some pretty amazing uses, even if supplanted by another, incompatible block chain that's superior in every way (Bitcoin 2, let's call it.)
Even if bitcoins somehow fell to a price of <$0.01USD again, I think the idea of it staying that low for the rest of my life is far-fetched. But even if it did, I wouldn't be concerned. If nothing else, at that price I'd just buy up every last one I could and make use of them myself. A credit-keeping system among my friends. As currency for an online game I would develop. Whatever.
A world-wide crackdown might stifle and suppress use of bitcoins so that it's practically never heard from again within the bulk of society. But make no mistake, until the internet becomes obsolete, bitcoin will NOT die.