Difference is I can do traffic analysis and RST generation over lots of machines (if it gets slow, worst case my RST gets there late). Changing routes/forwarding table action has to happen on machine moving large data, in real time.

You can sniff the traffic out-of-band, possibly implement it on already existing spy/monitoring infrastructure.

And ignoring RST may work. In fact that method worked against earlier implementations of the great firewall of China.