So if someone gets so frustrated that they decide that they are just going to quit working, quit cleaning, quit bathing, and quit eating, you'd tell me not to try and dissuade them from such actions?
She's talking about quitting one of the only two parties that actually have any control over laws. To do so removes all access to power, which, like it or not, is the only means to get things done. You can't make changes without the power to do so.
Joining a third-party is exactly like Pontius Pilate asking the crowd who to free and washing his hands. It is a symbolic act, a self-gratifying statement, that removes a person from virtually any ability to make change, other than weakening that party that they were once a member of, and by weakening one of the only two parties it strengthens the other party, which stands for so much we claim we oppose.