And it's not that I can't understand the subtleties of defs, it's just that on a forum I'm trying not to invest too much time and energy, so I'm in a bit of a hurry and take shortcuts. If I appear to deal better with the subtleties of def than FL did, it's only because I'm investing more time and effort in this thread right now than he was. I know he's perfectly able to do it as well, but since he never intended to "sell" you anything, just offer his view, he didn't feel the need to be super accurate (Don't take my word for it, I'm just assuming and jumping to conclusions about his motivation now. Hm... and realize I phrased it as "fact" instead of as "perhaps FL could have just been...").
As for the works/doesn't work mentality, I guess you see it that way, but it's not really an accurate description of how we think. We see the subtleties. But I guess on a forum we can have a tendency to boil it down to that just to get more quickly to our points.
A problem we meet on a forum however, is that IRL we both use and perceive a lot of non-verbal cues and communication. This is often crucial information lost, which leads to misinterpretation at both ends. Do you have problems with RL INFPs as well, or only online ones?