How to word a survey question
Of course the majority of people want the NBN, who wouldn't want FASTER internet, especially when many think it is some magical FREE service the government is going to conjure up out of thin air. It is only when people realise how much the NBN is going to cost 'per head' in tax dollars that they wonder if that same 'per head' total may be better spent in other more important areas or if there might be a more efficient and cheaper broadband solution.
Fortunately for the current government most Australians don't do the simple arithmetic of $45B + (the ACTUAL extra it will end up costing) divided by the number of taxpayers who will pay for it in order to discover that 'per-head' figure themselves. Most are also willing to overlook other potential problems such as 'the return of the Telstra Monopoly' for the simple promise of 'faster' internet.
A better survey question might have been to ask "do you think that a faster internet is worth $45B+", but that probably wouldn't really discover the answer that whoever was funding this research wanted to hear.
Like others here have said, real support for the NBN will be shown by the actual 'take-up' numbers once it has rolled out, but even then the numbers will be easily skewed, especially if competing providers are willing to accept generous government 'incentives' to switch off their existing copper services forcing everyone on to the NBN. For a government so confident of its NBN and the public support for it, they're incredibly quick to also ensure that any competition to it is effectively removed......so much for letting the market and consumers decide.