When a lot of more the population served in Vietnam the country turned against the war. Nowadays nobody seems to care that America's longest war continues on.
That's because they're not even remotely comparable things, as you note. Afghanistan is a security operation, not a traditional war. There's no draft, thousands of US soldiers aren't dying in Afghanistan. Even the cost is a modest fraction of the total US military budget.
There were 15 US casualties in Afghanistan in 2017, and 14 in 2016.
I'd say overall it's a good thing. It's a very good thing that 99% of people will never be able to remotely comprehend what we went through.