yes there is no doubt about this that loans are too risky so you should be careful when taking loan as there is always a chance of loosing bitcoins if he price fell down so try not to buy or do trading on loans as you will then not be able to return it back.
what is the risk in taking a loan 
the risk lies for the individual giving out the loan ,doing trade and gambling with loaned amount is a very risky thing as you never know when you are going to loose everything,bitcoin and price really never matter if you are not looking for a profit every month.That is true. Most people cannot control their mood and not very displined, it is better not to borrow.
It does not always depend on the nature of man. There are also all kinds of life circumstances. Can someone get sick - then they need money very urgently