Why does australia pay so much for data?

Would you pay $50 a month for unlimited internet from your mobile? Of course you would.

So why do we seem to be capped in Australia with data and time per month when the rest of the world enjoys free internet? I had discovered that a friend of mine who is traveling in the UAE is getting 4G internet for $50 a month.

So how is it that even Optus charge $60 for 10gb per month. Telstra charge anywhere from 250mb = $5 up to 6gb for $60 for one months of data. The best current Australian plan is Vodafone's $65 for 12gb. It's pure exploitation.

It still doesn't explain why we pay so much? Is the infrastructure? Investor expecting a high return? Greed?