Such melts happen more often than you'd think, especially with mass produced power adapters. Just google it and you'll get pictures like this one.
As opposed to what, hand-carved mahogany adapters? Being mass-produced has nothing to do with it, being cheap-ass junk is what's causing it. Using google to justify the fire hazard you're selling is just pathetic.
Less pathetic than you showing a picture of a single melted PSU to justify your biased opinion. There were thousands of sales and not a single fire.