BTW,
what makes a "leader" depends on who's defining it.
If one thinks "a leader is not a boss, and a leader cares about the people while a boss just bosses them around", then there are not as many leaders out there since many are bosses. twi provided great training in how to boss people around. It did NOT provide training in how to LEAD because vpw knew how to boss people around, and avoided ALL programs that would have taught him to LEAD, whether in college, or after, or outside of a school setting. vpw had neither background nor training in actual LEADING, so he couldn't pass on what he himself didn't know. When looking at lcm's biographical snapshot of vpw, when lcm thought he was showing what a great LEADER vpw was, he was exposing what a BOSSY BOSS he was. When something was unpleasant, vpw was quick to insist that OTHERS had to do it, and NEVER led by example. "Here, I'll do it and show you how"- something vpw NEVER said about anything difficult or unpleasant. He was quick to yell at others and claim it was to TEACH them or TOUGHEN THEM UP if asked (which was rare enough.)
So, for the amount of people who were trained by twi, the number of actual "LEADERS" is pretty small, and fewer still if you count those who climbed to the top of the twi hierarchy. There were probably lots of good LEADERS in local homes running "fellowships" and maybe branches, but above that, you were climbing the ladder. In twi, that was the result of ambition, which, IMHO, doesn't mix that well with actual leadership ability.
If you count "leader" as "one who vaults to the front, monopolizes the microphone, and tells people what to do," then that's a different story. LOTS of those people were groomed by twi to do exactly that, so there's plenty who decided to continue that after leaving twi. IMHO, that was the rule, not the exception, the higher up the twi ladder people got (of course, there were exceptions.) So, if "confidence and demeanor" are considered critical for "leadership" (i.e. "he looks and sounds like a leader, and that's good enough for me"), then twi produced many "leaders." If they're a nice ingredient but not as important as caring for people and making wise decisions, then they are not.
Getting back to JAL, he's got a proven, PUBLIC track record of making unwise decisions in the context of leadership. On the other hand, he looks confident and has a casual demeanor. Does that make him an AWFUL leader, or a FANTASTIC leader? That's up to whoever is asking.