First, I disagree with your statements about INTJs not as effective in leadership postions that requires initiative, adaptability, a nose for trends, and possibilities. I think in change situations, INTJs often find themselves in leadership positions. They know what do to when other people are confused, due to the clarity of their intuitive perceptions in the face of ambiguity, and how they are able to effectively exercise NiTe together. EDIT: I've mostly made my career on these situations, so perhaps it doesn't apply to this type of INTJ anyway.
When it comes down to ENTJs, I realize I'm generalizing and many may not hit the pattern, but I think what really bothers me the most is them turning their critique against people - that is judging people as unqualified, bad, not right fit, etc. and the speed with which they take action. They seem to seek to move bodies into positions where they can fit the right cog in the grand scheme. If there is a cog they don't like, or thinks differently than them, they toss it way. Perhaps it is my reaction, but I don't react well to loud, controlling, leaders particularly well. I have also seen decisions arrived at on the disposition of people - "this one's no good, then fire them" when in fact is it is the ENTJ's inability to appreciate people who are different from himself. This one guy tears through people - fatal flaw because other than that, he's quite capapable. It is a bit of a hatchet man's approach to managing people in my experience, not caring about the people they impact in the least. Though this person can be very inspiring to a crowd, the problems are with those that work directly for him. He seems to lack some ability to listen, is intolerant of mistakes, has quite a large ego, doesn't stick up for his people at key times, and these things get him in trouble because he has no loyal team that lasts to follow him. He is not nearly as successful as he could be.I'm not saying all ENTJs all do this, but have seen it enough times to notice a pattern of similar behaviours in several others - jumping to conclusions, taking actions, without sufficient information or evidence to base it on. It always seems to be an ENTJ exhibiting these behaviors. I'm not sure why.
ENTJ Spaz Example as relayed by someone else last week. ENTJ screws up his need to approve his own paperwork. Screams at poor administrative assistant that they're not doing their job (they should do it for him) and then hangs up on him. Complains to the poor guys supervisor that he isn't doing his job and it impacts his assistant's performance review. Administrative assistant is in tears over unfair feedback. Yet, actually, the ENTJ was the only one who could approve his paperwork in the first place. He realizes this later of course after the fact but does not ever admit that he is wrong or go back to the person's supervisor to apologize. True story.
I totally agree with you that INTJs make great leaders when no one else wants to or has the expertise. I find them fair and capable, but usually reluctant leaders.
I ALWAYS try to give people a fair shake, and I admit when I am wrong . . . but perhaps that is because I was raised by an amazing man who taught me that a leader is only as good as his staff. He used to give me practical advise like, if your employees are complaining about their jobs, call a meeting have them vote on the worst job and then do it for them. They will be so thankful that there will be no complaining after that. He was always telling me to appreciate the talents of the little guy. I don't know what he was, but I know he was more of a feeler, acting the "hatchet" man sent him to the hospital for a triple bypass . . . . Maybe an ENFJ?