I mean, is courtroom attendance mandatory when given a summons? What are the repercussions for failing to turn up during the appointed date and time? I know that they have Voir Dire and names of American citizens are selected randomly from the electoral roll (the same one used for federal elections on selecting a new president in office) unless you renounced US citizenship which rescinds both your right to vote and potential jury duty.
Occupation does not automatically disqualify you unless your work connects you to the case in question, but some occupations are not going to make it through voir dire. Keep in mind that you might be sitting on a jury in a civil case. Rather famously, Barack Obama was summoned (after his presidency) and he went, but was dismissed by random draw.