I don't think all Aussies hate Murali. In fact, many like him. There's a wide variance of views - from ignorance "he's never chucked" (wrong) to "I've seen how bent his arm is" (irrelevant) to he may have chucked but doesn't anymore, or OK, everybody broke the old rules, but he chucks more than anybody, etc, etc, etc.
I guess on the internet I do find that more Australians proportionate to other countries have a very hostile relationship towards Murali, but other people's experiences may differ. In any case, the fact that a) he was called in Australia, b) it was an Australian umpire that called him, and c) he has an intense rivalry with an Australian spinner probably accounts for some of it.