In the future, there is likely someone who will be equally able to look back at some primitive activity we're currently engaged in right now and call all of us idiots for some reason or another.
If you eat meat, or plants, perhaps you'll be referred to as a barbarian.
If you drive electric cars, perhaps you'll be called a planet killer.
If you don't bathe in milk, perhaps you'll be called a Typhoid Mary.
Ignoring the context of the times is a naive way to look at things. In 1996, the Defense of Marriage Act was passed, and many rejoiced. In 2013, the Defense of Marriage Act was declared unconstitutional, and many rejoiced; in a lot of cases, the very same people. I was a complete homophobe in 1996, and attend rallies and champion gay rights in 2013.
Society moves quickly now, but it didn't always. Yes, I was stupid for my homophobic ways in 1996, but so was almost everybody else. It's hard to hold an opinion, even one you know to be true, when everybody else disagrees with you. It's even harder to be the oddball that tries to advance the cause for equality.
Just because the WASPs were once racists, that doesn't mean the same people would be now. Times change, and smart people change along with them. By not acknowledging that, the inverse of your argument is just as laughable.
"those slaves of the past that the chap in the article is lamenting were totally spineless lackeys and yes men, completely subservient to white people. For this reason alone, I'm bloody glad that they're not in power."