@paulears There's undoubtedly truth in many of the points you make however...
HMRC commit to standing by the results of that test if answered as accurately as you are able, the test is (at your choice) anonymous or tied to an individual, so you only need to record the result when it shows the 'correct' determination, and the test itself will either give categoric answers, or simply tell you that it's unable to determine. The only actual risk is in not carrying it out, and it biting you down the line.
As you say, it is for instances where you are the employer (or could appear so), so you wouldn't run the tool if you got kit and staff from Orbital, nor would you if you contracted a smaller company in the situation you outlined above.
Where it is relevant is if I book 'Steve' for a month's work, and I know that he's going to invoice for that work through a Ltd Co. I would be filling it in for my company's protection.
The rules have been introduced solely because of the feeling the HMRC were losing out on tax income due to the structure of Ltd Co and payment of dividends etc.
I understand that you don't agree with it, but I'm not sure that that's relevant. I posted it because some people may not be aware of it, and I think people should be so that they can avoid assuming liabilities that they would have had no cause to expect.