Geoff More or less. I think @goonbag and @exodus both sum it up prety well.
To elaborate, it’s a mixture of things.
1) I just think we have a kind of ugly accent in general. Even in Aus, when I meet someone particularly “ocker”, (which I do often because I a) live in Queensland and b) play Australian Rules Football) I’ve always found it quite abrasive and to use a very Australian word “daggy”.
2) I hate the way we present ourselves internationally. Truth be told it’s not entirely our fault - the US’ basic perception of us came from Crocodile Dundee. The British have always treated us like the unwanted wart of their colony and made us appear far more stupid than I think the average Australian is. That being said, it is also totally our fault. Whenever I was in a continental European city and heard an Australian accent, I would turn the other corner. To paint with a broad brush, we tramp around the world like privileged drunk jerks and it drives me nuts. These kinds of conversations with voices from all over the world really just fill my mind with those images.
3) I also think that a lot of the time, Australians are a painfully unfunny people outside of an Australian context. There can be some excellent, hilarious, Australian on Australian banter, but as soon as it’s in some sort of media and especially when it’s up right next to New Zealand / British or American jokes it falls flat so fast and leaves me embarassed haha.