That's just survivorship bias on a very long timeframe: Given enough time everything accumulates the status of "historical mistake", but what about the hundreds of thousands of words that didn't change and the days they didn't change in? Quite reasonably, we just don't pay attention to the mistakes that were squelched or whose trajectory never broke the ceiling of temporary slang.

There are some analogies to biology. Virtually all our DNA is the result of an error at some point (barring creationist theories) but that backstory isn't a reason to dismiss concerns against (or even for) a particular mutation. Surely nobody would downplay the drop of 3 base-pairs as "acktually normal when you look at the big picture for our species" when talking to people suffering from Cystic Fibrosis.