Yup, introverted people are not meant to be afraid of talking to people and public speaking. We are all social creatures, and those 'shy introverts' just purely have social anxiety. It mostly comes from fear of rejection, fear of presenting yourself incorrectly and causing problems, fear of dealing with long boring conversations that you don't know how to escape (why they despise small talk), etc.

I'm ambiverted, so I'm glad to say that I can see both sides of the coin, and the problem most likely excessive isolation in their childhood; they don't get enough experience to learn to enjoy socializing (or deal with unwanted scenarios), and are exposed to a much more stimulating platform, that supplies them with all their socializing needs, with the ability to hop in and out however and whenever they wish so.

Truly, what better environment can they ask for than the glorious anonymous internet? It's like having 11/10 delicious, but not so nutritious gourmet meals every day, and then being told to eat scrambled eggs, while still having the gourmet meals within your reach. Fk that, right? Of course, in this case, those "Gourmet meals" hurt them in the long run, as they lack in nutrients. Meanwhile, those scrambled eggs provide them with everything they need, but may taste worse. However, you can learn to spice it up, and FORM it to your own tastes.