With guarantor for loan you can get credit again even with poor credit with things like arrears, defaults and CCJs to your name. It's a more sensible approach to finance and will again let a large proportion of people access to finance which would not otherwise have been there.
The useful idea of guarantor for loan came about as a result of fallout from the credit crunch we've known about for some time. Lending practices had to change to allow folk with poor credit histories to borrow money. The answer was the unsecured guarantor loan and it has shown itself to be popular.
With guarantor for loan you can get access to money easily no matter your credit history. If someone consents to be your guarantor, like a parent, close friend or relation who knows you quite well, then you will not need to be credit scored, so your credit history need not matter.