First, some people are introverts. They genuinely do not work well under conditions of heavy social interaction. This does not mean that they are "antisocial" or that they are sad; it means that they are more sensitive to some kinds of stimuli and so are more easily distracted and exhausted by it.
Such people should be understood and given the distance that allows them to work, not browbeaten into keeping up with the extraverts.
More than that, some people are antisocial and/or sad, yet are very good engineers. So employers and colleagues should be really interested in having those around, especially if they don't want to bother you with non-technical things.
Such people should be understood and given the distance that allows them to work, not browbeaten into keeping up with the extraverts.