Merchant adoption and volatility. There's just no real reason for most people to use bitcoin yet unfortunately. I fear it may always be a niche thing. Hope I'm wrong, though.
volatility can be negated only with adoption, great adoption, so the issue is only one, adoption, and always will be unless 1B(or around that) people start use bitcoin
bitcoin can also work as a niche thing imho, i don't see the problem with that, maybe not forever because miners need an incentive in the future to keep mining with a smaller reward...
Imo. Volatility and adoption are not the current issues of concern.
Security is.
If we try to get wider adoption into the joe average population before we solve the cold/warm wallets etc issues of trying to keep slightly safe then it will end bad once many people loose their Btc that they were supposed to keep safe themselves with their insufficient computer skills. Getting wide adoption too early before the security issues are solves could destroy bitcoin. We have seen other good inventions that dies forever because they were out too early.
Volatility is only really an issue as adoption increases and Btc is used for everyday purposes by everyday people. Then we need more stability. Right now investors and early adopters don't mind some volatility to make money off of it.
So until security issues are solved, adoption and volatility are not really pressing issues.
you rised a good point, security is what is holding back adoption, which is what is holding back bitcoin, from skyrocketing
security however is not only a bitcoin fault, but it's primarely a "average users" fault, if we repeat to them that they cannot store bitcoin online because it is dangerous but they still ignore use, this is only their fault, if they cannot keep they computer clean than it is again their fault
there should be a good guide about this, on the biitcoin.org, that tell newbie how to secure 100% their bitcoin, because apparently they cannot get it