Based on observation of the people I know:
Profile of an ENTP with an optimized E:
1. Comes from a rich family
2. Uses family resources to pursue his passion
3. Profession is related to that passion. And other sideline jobs are also related to that passion.
4. Has a very broad social network (i.e., connections)
Profile of an INTP that implodes in his introversion:
1. Possibly comes from a non-affluent family.
2. Because of the family's financial standing, he cannot realistically pursue his passions. It's already hard (well, maybe not exactly hard, but it's not that easy) for an INTP to pursue his passions because of the Ti filtering.
3. May have started working early because of the family's status quo. Worse, that profession requires extensive Te.
4. If he's still in college, he's probably taking up a college degree where it's Te intensive, but because he thinks he's smart, he probably thinks that he can do well in it in the long run. Until eventually, he got drained.
5. Probably haven't learned MBTI yet. Hence, taking up the wrong degree.
6. If he lives in a ghetto community, he's probably feeling the pressure needed for social compliance by the community, which is probably SFJ in nature. It's already burdening to have the other factors listed above, and this one adds another layer on that.
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Consider the ENTP guy above.
Let's say he has this quirky expensive habit. Let's say photography. Everyone knows that this is a very expensive hobby. High end cameras cost higher than an optimized PC. And you'll also be needing an optimized PC for that.
In case that the regular SF acquaintance that he has isn't able to relate to the hobby, that ENTP guy can get in touch with his other contacts (which can also be quite affluent), that are possibly as quirky as him, and thus his extroversion is better practiced.
The INTP guy below isn't enjoying the same level of perks. Although the ghetto community may provide a significant number of acquaintance, they may not necessarily fall into the quirky NTP mode that the guy is oriented to.