True, the government could order the phone companies to rewire the phone system so that each caller would receive a message posted by the recipient without ringing the recipient's phone (making it work more like a NO SOLICITORS sign). The DNC list is less intrusive.
The above would be a great idea (with the telemarketing company charged for the do-not-call message at the same cost as a regular call). That would settle things down. But, I never said the gov't should "order" the phone companies to rewire anything. The idea is a good one, though, if it's feasible.