That is true, it is a bit like being negative on the market. Things all move in cycles, it is a matter of where you are in the cycle. House prices for me are driven by return on investment of the asset and underlying growth in real disposable income to support the asset. Once both branches are over done, I think it is a matter of time before the correction comes. If the argument is that the Chinese are parking their savings, I think US and Europe offering better risk/return than Australia. The question you have to ask is who is positive on house prices and their motives...Brokers, Governments and central banks have to hope that they hold up till the global growth picks up or it could get very messy.
On Sydney property... If you say it is a bubble for long enough one day you (might) be right.