Why aren't people as curious about extroverts as they are about shyness?

Because everyone sees an extrovert... an extrovert tells you what their thinking.....there's really no guessing, unless the extrovert is a liar. But an introvert is mysterious....people love a good mystery.... they could keep 1000 cats in their house or have a ex-celebrity chained to their bed, ...you can always guess what skeletons an extrovert has in their closet...but although usually an introvert isn't much different...its the appearance of mystery that catches attention

Because typically extroverts speak everything that they're thinking, which leaves nothing to the imagination about the person's experiences, thoughts, feelings, or overall identity. The shy people that I have known usually have a great amount of emotional and intellectual depth as a result of their experiences that shaped their personalities. There's also the belief that when someone is not speaking or is sitting outside a crowd, it is because they are engaged in contemplative thought or brewing over some emotional difficulty in their head.

Either way, it is assumed that the introvert is thinking something unique that will lead to a more stimulating or emotionally connective conversation if that person can be made to talk. I think the reason for the lack of curiosity about extroverts is that people assume that they must always act and think the way that they do in front of others.

Because there is nothing curious about extroverts. They are in your face 24/7.

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It is thought that shyness has a root cause, such as being in a certain catigory, like having a single parent, seeing someone you love die, or even being fearful of large crouds and having to talk to too many people.

I was shy for many years due to dyslexia; but after adjusting my way of living and adjusting to the malady I am a featured speaker at several universities, You can't help a shy persons; they must help themselves.

Simply put, the only people who would be curious about extroverts are shy. Since they are shy, they rarely ask. If they don't ask, you can't hear about it.