IF Muscletech or Iovate filed for bancruptcy, if is most likely an ephedra lawsuit defense. The owners of Xenadrine (Cytodyne) did this when the wife if the baseball pitcher that died sued for $600 million (yes, the fat pitcher with too much clothing on and didn't eat for days - his wife wanted that much in a wrongful death suit). There was obviously not enough money (insurance or in cash) to settle - hence the bancruptcy. This led to the sale of the BRAND to Pinnacle.
Other companies have done the same - I believe AST is one of them due to lawsuits.
There is a slight chance that the filing may have come from poor asset/cash management. Let's face it, these guys pay a ton for ads, athletes, slotting fees, marketers, etc. If they got too far ahead of themselves or didn't see a good return on some investments (like research?), they may be in trouble.
Companies like GEN went out of business based on the business, not lawsuits from what I know.