Prior to the introduction of TPS, some people were receiving dozens of sales calls (for double-glazing, solar energy, home improvements insurance policies , etc, etc) every single day, seven days per week, often going late into the evening. TPS has eliminated all such calls from responsible UK-based companies but scam calls almost always originate from overseas (even if the number is shown as being UK-based), so it would be unreasonable to expect TPS to be able to filter out such calls.
Without TPS you could be receiving hundreds of sales calls every week, Grumpy01. Don't knock it!