I'd say that's a pretty black and white way of looking at things and while your definition of introversion is correct I think some of your views towards the end there are a little unfounded. Some people just have certain limitations and it's less about changing yourself to make things easier, but finding better ways to deal with it. I can honestly say I've tried for years to take hold of my more extroverted characteristics but it's hard. The human mind is an amazing, but complex thing and it often take years of therapy just to change the smallest thing about someone's mind. It's not as easy as just telling yourself you're going to be an extrovert today.
But that's exactly what I was saying.
It is black and white, because, and I should have clarified it, I meant that in a vacuum. When it comes to actual disadvantages, it already changes things completely.
I never said anything about choosing to be someone else one day. I'll give you an example to illustrate what I mean. Lets take the whole lack of empathy thing. Some people are natural in this. They understand other's feelings, pick up on the smallest of clues by default, without needing to think about it. They simply feel it in their bones so to say. But to people like us, it comes in a circle. We do pick up the raw data, but in order to process it, we need to compare it to other aspects of life to understand it. Whether we do it via ourselves, our past experiences, experiences from the collective history of humans, media, etc... depends on each individual.
To put it very bluntly, if I see someone frown and can't tell if they're sad, I remember a movie where someone was frowning and he was sad, therefore the person in question is also sad.
Now in a situation involving only ourselves, it doesn't really make a difference. But when a response is in order, being in tune with any other viable source of experience will help us.
All in all, I wanted to point out that everyone has different tools to cope with situations, even though not all of them are readily available. And in the end it was more of an "academical definition" and not an observation if that makes sense.