Interesting discussion, and the analysis seems reasonably accurate, as far as it goes.
This is only one area of investment research that a reasonable person would use. It appears to me that the author isn't saying that the only metric to use in your analysis is the debt/equity ratio, but it should be considered along with whatever other metrics matter to you--rate of new product development, free cash flow generation, competitive position, condition of the industry the company operates in--and base your investment decisions on your own research.
10 Dangerous Stocks to Avoid [View article]
This is only one area of investment research that a reasonable person would use. It appears to me that the author isn't saying that the only metric to use in your analysis is the debt/equity ratio, but it should be considered along with whatever other metrics matter to you--rate of new product development, free cash flow generation, competitive position, condition of the industry the company operates in--and base your investment decisions on your own research.