One of the links in that article
really amused me. The one that talks about the "alliums experts" at GardenWeb.
I'm one of the people who got that forum started, and, I guess, am one of the "experts" over there. ;>)
Anyway, there are a lot of myths and misunderstandings about garlic. And often, as in the case of that article, ambiguities sneak in.
In this case, the ambiguity is where they say, once it sprouts it turns bitter. Well, yes and no.
Once the clove actually sprouts (this is, green growth is showing above the point) the quality of that clove is gone. A lot of chemical and structural changes have taken place, and there's no sense using it.
Before that happens, however, there is a green core in the clove, which will become the sprout. At that point, there is some quality loss in the clove, and the green core, itself, can add bitterness.
Often we have no choice but to use it. Around this time of year, most garlic---particularly store bought---will show that green core. When that happens, I split the clove and pop the core with the point of my knife. And I up the garlic content even more than usual, to make up for the loss of flavor.
Oddly enough, green garlic (scallions grown from garlic instead of onions) is a delicious addition to many dishes, providing a garlicy hint that contributes without overpowering. Green garlic is not bitter.
Go figure.