Why does the plaintiff have to appear in court for a default judgement? I already sent in the evidence that proved my case.

Because the judge requires one of the parties to appear to have the hearing.

Also if they showed up and you did not show up, they would win by default, since your evidence means nothing if you are not there to produce it in court.

And at the end of the day, it is their rules, you either do it, or don't get a judgement.

Also have you figured out how to get your money after you win the judgement ?

Why does the plaintiff have to appear in court for a default judgement? I already sent in the evidence that proved my case.

Because people are assumed innocent until proven guilty. The defendant could argue that the evidence you supplied was faulty and/or forged.