It's certainly the case that many people might argue the main advantage of bad credit guarantor loans is that the borrower's prior credit history is rendered utterly irrelevant. All former defaults, arrears and missed payments no longer matter at all. As long as a guarantor with a good credit history is nominated then you have access to credit once more, when that would have been previously impossible.
With bad credit guarantor loans you can get credit again even if you have a bad credit history featuring things like CCJs, arrears and defaults. It is a liberal approach to lending and will again let a large proportion of society access to credit which would not otherwise have been there.
With bad credit guarantor loans you can get access to cash quite readily irrespective of your past credit history or if you have no credit history at all. If you have someone who will act as your guarantor, like a parent, close friend or relation who knows you well, you will not be credit scored, therefore your own credit history will not matter.