The point in the article is short and sweet: if you are doing TDD you should write your tests yourself. Don't use tools to generate tests for you unless you understand exactly why and what the savings/efficiency gains will be.
Many times over the past years we have seen the tendency to use tools to replace intelligent judgement on what should be done. Good examples are the code generators (based on UML diagrams and such) and the test case generators.
We should never use a tool unless we know exactly what we are doing and can do it ourselves without any tool. Automating a process that is misunderstood only makes things worse.