Lynching was good because it showed that the people still held fast to the spirit of justice. Nowadays, people think that obviously-guilty criminals deserve to be set free just because they hired a lawyer who made some clever arguments. See: OJ Simpson, for example.
Discussion
I'm not sure anyone thinks somebody like OJ deserves to be free. They just think so much in terms of sportsball and peace-forever-always that they think technicalities are fair game and there's no overturning them. Process-trusting is more important to them than right vs wrong.