Obviously, this idea is picturing a worst case scenario,which, however, is more likely than we would be willing to admit. Besides, this is not about Bitcoin only, so do not expect a rant about how broken and ancient it is ;) Anyways, it is out of any question that once Bitcoin falls it inevitably gonna drag all other currencies to hell alltogether.
Let´s look at the situation to back this up a bit.
What is the currrent state of crypto? Unscalable blockchains, ponzi schmemes and now on top vulnerabilities in the biggest hope for crypto world. The timing for The DAO exploit could not have been worse. Just when the public and legit companies were slowly gaining convidence in the crypto space again (first and foremost based on the success of Ethereum). What a turn-off, right!? ANY trust in ANY crypto currency is fundamentally broken (for now). When adding that Bitcoin must be considered entirely hopeless due (denying it won´t help), we are facing a very probable "blockchain hype" bubble burst.
We conclude, Crypto World appears rather rekt... Further negative impact does lurk in the real world as well though. To me it is rather obvious, that a Brexit is the declared goal and will become reality. The impact on the financial markets will be historical. While US indices skyrocket, the EU stock market will plunge like never before and the Euro dump into oblivion. Since it is still widely considered THE safe haven, the rush into US Dollar and any sort of US assets will be beyond belief.
Against the (somewhat) delusional expectation of the crypto community, peeps WON`T put their moniez into Bitcoin or any other crypto currency since now "proven unsafe" (only talking peeps perception here). It is not at all unlikely that it turns out the complete opposite. Meaning that a lot of investors gonna dump all their crypto for USD leaving whole Crypto World crippled.
Again, that is the worst case scenario. Just take it into consideration to prevent a rough awakening.
Hope for the best, prepare for the worst.
Good Luck, everyone!