Those would only damage bitcoin, people arent able to repay their loans and with their salarie as colateral, i dont see any advantage to bitcoin users to let banks choose the people they will lend and wich colateral they will take. There is already an option to get interest with our bitcoins, some exchanges does provide those, and i believe thats the right method for bitcoin, allowing people to cashout and use those money will be the same as donate, imagine a person ask 10 bitcoins and then bitcoin grows lets say 60-70%. For such thing work the loans should be in bitcoins and the repayment in the bitcoins as well, meaning if they get 10 btc they should repay 11btc and not its value.
Isn't that somewhat along similar lines about Bitcoin scams like cloud mining damaging Bitcoin itself? But most people here say that such accusations are unfounded, and Bitcoin has nothing to do with that. So why should it be different with Bitcoin banks? In any case, such banks will not be able to turn into scams overnight. Apart from that, we can't really change much in this respect, since many people will be just happy to deposit their hard-earned bitcoins into a bank regulated by government. Also, I don't see how the interest earned from an exchange differs from the interest earned through a bank deposit. By the way, exchanges also give out loans from the funds of their clients...
Though it is primarily known as marginal trading