A certain level of regulation is indeed needed for massive mainstream adoption, but nonetheless they can never stop people meeting in real life and exchanging BTC for cash anonymously, unless they start putting coverup feds in LocalBitcoin selling BTC to scare people away.
I think relevant and legitimate services/apps are needed for mainstream adoption. Bitcoin can completely operate outside of gov't control. In fact, it can PROVIDE gov't control.
+1. And it's ridiculous to say that banks' hostility towards bitcoins is based on an aversion to high-risk financial activities. Who has engaged in more high-risk activity than the banks? Sub-prime morgtage fraud, laundering hundreds of billions for drug cartels, Forex trading scams, and tax-evasion services for the wealthy are a few examples of high risk stuff the banks have been involved in. Banks love high-risk investments as long as they get all the profits and tax-payers foot the bill if the risks don't pan out.
The Banks only "fear" that if they don't follow government regulation then they'll be heavily fined. They haven't adopted BTC in anyway because they fear any kind of investment they put in may randomly be wiped out by new regulation or an out right outlawing of BTC adoption by the government. So currently, the push back at banks is solely based on the fact the government-bank relationship hasn't formally declared operational restrictions, aka regulation, on the crypto-currency world. If banks were involved they would be acting a state of constant unknown.
It's not that BTC needs to be regulated for wide-spread adoption... it's simply that banks are already acting in a regulated environment and need to know how any new regulations would effect them before they get involved. You won't see widespread adoption until the average user can have a BTC balance sitting right next to their fiat balance on a bank account.