A loan at an 11% interest rate pays for itself in around six and a half years. The general concept is that even if the PE firm runs the company into the ground, it only needs to exist (and make loan payments) for 6.5 years to get your money back.
For a company like Toys R Us, there is still value in that brand name. You can reduce the quality of the store and coast on that recognition for a little while before people change their shopping habits. Put another way, how many bad meals would you have to have at your favorite restaurant before you stopped going? I bet it's more than one or two, as long as the experience isn't super terrible.
So for a lender, the questions you ask yourself are:
1. With cost cutting and other measures, how long do I think this business can last?
2. Once this business reaches bankruptcy, how much am I likely to recover on my loan? This involves figuring out how much in assets the company has.
3. What are the chances this business is able to be turned around?
There are situations where even if the company goes bankrupt, the lenders still made money.
Lenders aren't dumb. They know the reputation of the PE performing the buyout. If that particular firm has a terrible track record money to lenders, the lender will want to be compensated for that risk.
Ultimately, the people that "pay" for this are shareholders (who get zeroed out in bankruptcy) and consumers (who get degraded product/service quality for the same price; that's how the company stays afloat in the short term).