Honestly most people aren't that smart. They'll just think, "Oh look, now my cash can be digital like PayPal" and not even associate it with bitcoin.
That's the thing, they won't have to. If, as these guys are planning, their Realcoin gets picked up by banks, exchanging USD to/from Realcoin will be done right from your own bank account. Remember, if these guys get enough asset, audit, and bank backing for their coins, no one will have to bother actually redeeming Realcoins for USD. Banks, after getting some Realcoins from his company (or another bank) can just swap in an out of them for you, right within your own bank account, knowing that they can always redeem them back into real dollars if they ever need to.
And once people do the simple swap right from within their own private bank account, suddenly their fiat currency is unlinked from any specific bank, and can zip along the blockchain to be traded directly with other people for other things (unless the regulators get too pissy about not being able to monitor everything)
Brock is 100% behind bitcoin, which leads me to suspect that this is perhaps his attempt at making entry into bitcoin easier for the economy as a whole (which would be a bit difficult to shove through the tiny narrow centralized exchange "pipes" we have now). Also, remember how Doge used to be really hated by bitcoiners, until we realized that a lot of people who thought bitcoin was a joke ended up getting into Doge, thinking "at least it knows it's a joke," and then those people suddenly understood first-hand how cryptocurrencies worked, and "got" bitcoin?