That was only part of it. A significant number of the protesters hated our government and didn't care about our soldiers. You don't spit on soldiers and call them baby killers if you care about them. Another part cared about both sides. You ever hear about Hanio Jane? She and many others called out the US for bombing non-military targets killing innocent civilians.
Another tidbit about Vietnam is they had whole cities underground. Check out Cu Chi tunnels. They also used women and children as booby-traps. Any of this sound familiar?
I wasn't there, but here's the timeline I was taught:
War started in 1954
US sent troops in 1964
First protests started in 1965, and largely focused on US involvement, well before the mistreatment of US servicemen began
Protests continued heavily until Nixon started withdrawing troops in 1970
By 1971, protests had mostly died out
US completely withdrew troops by 1973, no more war protests (more focused on Watergate)
War ends in 1975
Now tell me the US public was really concerned about civilian deaths. Were some individuals and small groups concerned? Sure! On a national level like we're seeing now? Heck no. And we didn't think to care for the first 10 years of the war before our boys were sent as VC guerilla fodder.
This ain't that.
ETA: and the protests and focus on civilian deaths didn't end the war, just our involvement in it, so his point stands: focusing on civilian deaths doesn't help end the conflict.