A lot of the "mistakes" people are pointing out are really folk-processing of materials that have been around for centuries. Case in point, Kendall's 'It's actually "All that GLISTERS is not gold."'

Well, not actually. The first recorded instance of this proverb is in Latin, and the verb was "splendet" or "shines."

The first English version was:

Nis hit nower neh gold al that ter schineth... (it is not all gold that shines)

Chaucer used it with both "Glareth" and "shyneth," and Hills with "gloweth."

"Glisters" doesn't show up until the proverb has been around in English for 400 years. "Glitters" comes in 200 years later, and has been the standard way of speaking this proverb for more than 200 years at this point. Actually, "glitters" has been the standard form for longer than "glisters" was. The only reason some people get stuck on "glisters" is that Shakespeare was so influential, and he quoted the proverb as "glisters."

"All that glitters is not gold" is a perfectly good example of the folk process changing a proverb as the language around it changes. Since "glisters" is not a word people commonly use, it drops out of the proverb tradition. This same reasoning goes for things like chomping at the bit. Do people (or horses) champ on their food? Not anymore. We don't use the verb "to champ" in any other context, so why would we continue to use it in this phrase? Now that the language has changed, so does the idiomatic phrase. To get mad about it makes as much sense as getting mad that we don't say "schineth" anymore.