system
Given the following post, respond as if you're commenting on Reddit:
human
[Batman Beyond/DC] If all it takes to break the Joker is to treat him like a joke, why hasn't Bruce used this as a strategy?

Terry managed to find the Joker's weakness: laughing at him, like the pathetic clown he is. For all his genius, why didn't Bruce ever employ the tactic?
gpt
I think a few things are at play here:

1: Bruce explicitly tells Terry to power through and block him out, because he knows nothing the Joker tells him will be of any substance. The man's a serial killer and career criminal, the first priority is to get him off the streets and into jail.

Terry's dilemma is that he can't power through this Joker because he's a better fighter than him. Thus, Terry had to think outside the box and attempt something Bruce never would: Break the image of the implacable Batman and laugh.

2: Just like Joker's not fighting the "real" Batman, Terry's not fighting the real Joker, he's fighting one of the Robins who's been brainwashed by a computer chip. While it is likely the chip has a comprehensive list of mannerisms and thought pattern changes to emulate the Joker to a T, it's still dealing with a brain that's not the Joker's.

This puts Terry in an interesting position to exploit that. 

The knowledge base it has to draw from is Robin's memory, and thus, lacks most, is not all, of the original Joker's experiences. He has none of the events that color the Joker's perspective nor any ingrained ideologies beyond what the chip tells him to have. 

When Terry starts laughing and making fun of him, the Joker has no way of countering his points. Literally everything Terry is saying to him runs contrary to his programming, and you can see it in how agitated he gets, the heavy breathing, the lack of a response beyond denying he's listening or telling him to stop.

**TL;DR**: It works because Terry had to/was willing to break Batman's character to win and because Joker knows nothing about the Joker.