I think there should be a fee for outgoing emails and phone calls. So small, like $.001 per. The common person like you or I probably wouldn't even make it to more than a few cents per month (if that), but spammers who send out literal millions of emails and phone calls PER DAY would take a good sock to the nuts.
Of course I know they will eventually find a way to game the system but it's ALL about money and it has gotten this bad because they can spam the entire world for almost free. Even if they only get 1/100th of 1% of grandmas to fall for their scams that's still thousands of dollars a day and they don't need much to keep the lights on at Indian call centers. If it wasn't profitable it would have gone away by now.
Verizon, AT&T, Quest, Sprint, etc. make quite a profit from these robo-call companies. They're not about to cut their nose's to spite their face, unless they're forced to by the FCC and that's not going to happen with this pro-business administration. They could stop it tomorrow but have no interest in doing so.
Also charging them on an outgoing per call basis won't fly. They've purchased business grade T-1 or PRI circuits from these same companies (Verizon, et all). They pay a one month charge for these circuits with unlimited calling, just like collection agencies do, another kettle of fish with its own abuses.