So... if that is possible, why would any company choose to acquire the debts and obligations of the company they are purchasing?
Because oftentimes they are buying a functioning business and they must. The secured creditors must release their security interests, the unsecured creditors can file suit and argue that there is successor liability, etc.
The situation is entirely different when the business is failing. Sure, you can't fraudulently sell assets for less than their reasonable value, carve up lines of business in odd ways to separate the revenue-generating portion of the line from the obligations of the line, etc. But you can sell off profitable lines of business for their value, or sell off assets for their value, while keeping the obligations and satisfying those that you can. That's exactly what happens in a Chapter 7 bankruptcy -- functioning parts and things that can be salvaged are sold so that they remain productive assets for someone, with the proceeds going to offset the debts. Since the cash, proceeds, and value of any remaining assets are usually less than the sum of the debts and obligations, there losses are allocated amongst the creditors. And customers are just a different, unsecured class of creditor.
Pebble will end up in bankruptcy, sooner rather than later. Lawyers for the creditors will look at what happened in a period before the bankruptcy to see if there is any way to recover additional funds, but so long as the transactions were reasonable, they won't be undone.