Not quite that simple
"The end users did not choose what the mobile operators paid for their 3G licences. The taxpayer did not choose what the mobile operators paid for their 3G licences"
The operators were free to pay what they wished for 3G spectrum, but they are NOT free to charge what they wish for termination charges. That's the issue they have.
Remember that 3G spectrum is extremely finite, whereas the crap you and I buy in the shops is not. Example - you own an art gallery. If you want people to visit your art gallery and pay for the privilege and thus keep your business afloat you need stuff your customers want. So, you enter into a bidding war for an original van Gogh. You pay what you have to and are free to do that.
So you;ve got your picture, but the Government won't let you charge more than 50p for a ticket to your museum! How do you make ends meet? You had to buy the picture 'cause otherwise nobody would come to your gallery and you'd go bust, but your turnover is artificially limited by the Government so it looks pretty darned difficult either way.
The operators put faith (and a **** load of cash) into a system to help the UK improve its comms and associated businesses. In return they expect some kind of improvement to their own bottom line, seeing as they took the risk and all that. If you don't give them something back, why the hell would they look to take any risk in the future? That means el Gov building the 4G networks at its own expense, rather than making a fat load of cash out of spectrum sale as it did last time around.
So, pay for 4G with your taxes, pay for it through your phone bills or don't have it? Your choice.
PS - yes, the operators paid over the odds for 3G spectrum, but that;s the Governments fault for using a system designed entirely to maximise their revenue. If the operators had met up in a hotel room and said "right lads, you bid £200 on that segment, we'll do the same on the next segment etc..." they would have fallen foul of competition law. They HAD to fight each other and artificially inflate the price or be left out.