The survival of the fittest stochastic process cannot be understood by looking at isolated examples.That hasn't been the trend though, especially in an economy where a successful advertising campaign often makes the difference between a product being accepted or ignored by consumers, regardless of things such as product quality, company management and policy, and other things that matter but they don't. Microsoft, Apple, Wal-Mart, McDonald's and Nestle are probably the pinnacle of such examples of poor product quality, immoral, unethical, and even at times illegal business practices, and business operations that most people would find appalling, yet they are some of the wealthiest corporations and most successful in business. AIG was ran by people who asked for bailout money to go on vacation, and the company is still around.
It's about general trends (emergent properties) over time. Better practices which confer a competitive
advantage tend to win out. Even if we introduce your claims of corruption (crony capitalism), employing
superior practices will still enable one corrupt company to out compete the corrupt company with inferior
methods.
Regarding the very real problem of inferior workers being promoted over superior ones, this is & will
always be a problem because evaluation is difficult, no matter how objective the process can be made.
This will persist in any kind of economy, be it free market or government run. But statistically, if a method
tends to promote the superior worker, then company results will tend to be better, thereby conferring
a competitive advantage, & better survivability in the marketplace.