Uh, if people don't answer telespammers then the robocalling issue wouldn't exist in the first place.
I don't answer 99% of them and the robocalling issue still exists. I don't care what other people do, your proposed solution doesn't help me because it requires answering all of them. And somehow getting a "popup" that cannot physically happen.
The thing is with my system most spammers will be shutdown quickly.
Hardly. None of the laws against it have shut it down, so expecting them to all use legitimate, law abiding phone providers is overly optimistic. That's what you'd need to have if you expect a "call rating popup" to have any effect. It's the same failure of legal limits to stop email spammers -- as long as someone is willing to sell them network services, no law will stop it.
In the meantime, forcing people to answer the calls means the phone list the spammer is using will be verified, and be worth more money. It's a help to the spammer. A solution to telespamming that has the side-effect of making it more profitable isn't a good solution.
And btw, a list of numbers without useful information about the person being called is useless.
Really? Seems that I get a lot of telespamming calls from outfits that obviously have no information about the person being called, because they want to sell me things I don't want and are done ignoring the major bit of information they could garner were they doing this legally: the number is on the national DNC list. So no, not knowing anything other than the number is valid doesn't mean the list is worthless. Knowing the number is valid is enough. In fact, I just got a call from "Julie" saying I'm preapproved for a "$250,000 small business loan", on a phone line behind the PBX at a major university. Every number with this prefix is someone who works at a University who has no authority to accept a loan on behalf of our "small business." The telespammers don't care, this telespammer has been told who this number belongs to and they still call it.
I mean, if you dial a random phone number 90% of the time it's valid number -- try it.
I don't need to "try it" to know that's nonsense. Just given the number of non-human phone connections out there (FAX, modem, ATM, etc.) I know that 90% is hyperbole. You need to support this extreme claim with something more than assertions, or anecdotal claims that one area code has this problem.
Such a list is useless to spammers.
1. The number connects to a person.
2. The person answers the phone to unrecognized numbers or doesn't have caller id.
Those are two very important pieces of information that your system hands over to every telespammer. And that information is worth money since it means they can concentrate their calling and not waste time and money calling modems, ATMs, FAX machines, disconnected numbers, or numbers that never answer.