I'm a self-declared INTP, but I think this just a transitional phase into something else. I think I would either shift into ENTP or ENFP later.
Well, the reasons are many. For one, I don't know any INTPs in person, hence I don't think I can reinforce my archetype in the long run. ENTPs, and ENFPs are easier to find. I probably have quite a number of ENFP friends. They're smart, charming, eloquent. I couldn't tell for certain if they're actually ENFPs unless they started talking about the meaning of life and various humanity stuff. They have a broad knowledge base like an INTP and they can also intellectualize, making me think that there's a strong Ti there somewhere that goes along with Fi.
Most of my ENxP friends are older than me, by at least 5 years (I'm currently 27), and they all seem to me like an actualized INTP (extroverted, and actually able to make something out of their lives), and at the same time, they see in me what they used to be before (or so they tell me). They could be INTPs before. I don't know.
Don't get me wrong though. They still have quite a significant degree of INTP traits e.g., hate for the corporate world, advocacy for humanism. It's just that they're able to do something with their lives (careerwise, and whatnot).
Is extraversion giving a leverage?
One of my dismays as an INTP--introversion plus perception is like a double whammy for not being able to substantiate anything later in life. Extraverted perception has better chances, or at least that's how I see things from them.
I have a theory.
If you'll consider the four NTs...
ENTJs and INTJs are probably the stereotypical cynics of the working world. They're on a rat race (where their Te is highly valued in the workplace), but since the hierarchy at work is like a pyramid where it narrows down at the top and someone gains at someone's expense, cynicism is being developed.
That's not necessarily the case for an INTP since INTPs are outside the ratrace and they'll probably just be satisfied if it's Ne/Ti that they're actually using at work, and as long as the profession is sustainable, he probably wouldn't care about competing with anyone.
TJs have a battlefield in work, and INTPs decide to go out of it, making them apparently less cynical.
However, you put INTPs in an environment where there'll actually be potential clashes of Ti and they can actually become as cynical. I think that explains why INTP Central isn't that friendly.
I think that an unhealthy INTP puts Ti into overdrive because...
a. They lack specialization that the TJs have.
b. They lack implementation skills.
The idea is, if they'll lack a and b, they'd use Ti as a compensation to get a sense of intrinsic worth, without them realizing that they've just created another rat race. Only this time, it's a Ti rat race.
ENTPs might have a different take on this. They must have gave up the rat race, whatever form it may be (Te-synthesis or Ti-analysis).
A laid back Ti allows Ne to flourish.
The way I see it, the difference of an INTPs Ti from an ENTPs is....
...a highly used Ti will extract an information's essence, connect the dots, and look at the various relationships it generates with the other concepts.
An ENTP will probably not use Ti to that extent, thus the greater the chances for Ne to move because of the increased Ne mobility, since the Ti is simplified.
I couldn't say exactly though if ENTPs actually build up their Ne as much as other archetypes build their strongest cognitive processes. ENTPs here may wanna explain on that.
Though, based on personal observation, ENTPs have the most defined, dynamic personality among NTs. I'm not sure how much of that can be attributed to Ne, but I think it's because TJs put aside their personal humanity for their personal goals, and INTPs dwell on the logical, leaving ENTP the sole NT archetype that has an actual space for character development.
I think this could explain why ENTPs can do self mockery. They're too confident in their character that they can actually self-mock it.
I observed that ENTJs don't have the same luxury. They fortify a rigid outer core.