Can't they take that that three quarters of a billion and instead build some low income housing?
So the argument goes like this...
$750 million of private dollars is $750 million the government doesn't have to spend, so technically, they could spend that government "savings" on low income housing, something that arguably should be the governments job and not the private sector's job (though voters in my home town thought differently).
In addition, restoring monuments and attractions only help to attract more tourists, whose taxes are a large source of the government revenue (Paris' hotel tax is 25%) so think of it as marketing for the individual, with a tax break, thinly veiled as an indirect investment in the government coffers.