Though I'd agree with your belief that Enchanting can mess up the market, you have to think about what things would be like WITHOUT Disenchanting. Right now the primary reason BoE greens sell is because there is a demand created by Enchanters, which is created because people want their gear enchanted. Without Enchanting I'm sure there would be a few that bought BoE greens, but in general no one would bother (the majority of them aren't good compared to those you can get from Dungeons and harder quests). If there was no demand for them, there would be a huge surplus, driving the price into the ground, making it likely people would instead vendor them.

BoE greens that end up on the AH usually get sold to enchanters who are going to DE them for cash anyway. There's really no reason to equip a "of the " item. Quest rewards are too good and too easy to pick up.

I don't think you're missing anything when you don't find greens in the AH.

I get the feeling the level of gear you're looking at is below 60. The article is mostly directed to northrend-quality greens (level 68 and up). For players between level 58-70, the quest rewards in outlands and northrend are plentiful and do nicely for leveling. Most greens from these zones only sell to the enchanting market or the occasional twink picking up a 59 piece of gear. For azeroth leveling, quest rewards are a lot harder to come by and underpowered compared to BOE greens. However it's probably not enchanters buying up the expensive ones on your server. The demand for mid-level enchanting mats is sparse and largely only used by people leveling their enchanting. Items with desirable stats are sold for a high price because of their stats and the relatively scarcity of supply. Most servers (excepting new ones) don't have a lot of people killing the mobs that drop stuff in that level range. There's a fairly limited supply of leveling greens, thus high prices for ones than have desirable stats. Has nothing to do with enchanters.

Actually one of the reasons that you might not find as much greens on the AH is that it seems like Blizzard lowered the drop rate for them. To fund my toons I use to run vanilla dungeons for enchanting mats to auction (due to the no cost of placing it on the AH). Doing Baron runs, Stockades, etc. Last time I ran Stockades I only got 3 green BoE drops, while Strat Baron runs give 6 green and 3 blues BoE.