Why is Dill so upset by what is happenning in the courtroom ? What does this say about his character?

Dill says he can't bear to watch Mr. Gilmer behaving so disrespectfully toward Tom. Scout says that all lawyers do that and Mr. Gilmer didn't even seem to be trying as usual today. Dill points out that Atticus isn't like that. Dill is compassionate and sympathetic.