No, there is not a problem with loans are not limited to 7 years. It's artifical centraly planed limit. It's is not good idea. Solution is money with stable money supply. So people can accumulate wealth with just holding it.

Without ability of banks to create money from thin air and with ability of people to accumulate wealth without investing, length of loans decrees naturaly. People will have more money for crisis and bank's will need more carefully choose how they use their resources.