What are your references? Although the technology is feasible, I wouldn't be so quick to say that it exists. Even if such software does exist, the phone systems are extremely complex due to the mixed technologies involved, so the software probably misses many opportunities to filter out scammers.
The phone companies want these spammers and scammers stopped. It's much better advertising for them to say, "See, we have a zero-harassment policy!" instead of silence. Your post might be sincerely written, but you can't know all the facts or see all the angles and so you only wrote out of frustration. I don't blame you for it -- I'm frustrated by this myself -- but your approach is misguided.