Wander00 - For the sake of playing devil's advocate -
When the government had (have!) no capital to spend on capital purchases, they went down the PFI route. Thus enabling the provision of the service required. Albeit under more restrictive terms than ownership would have allowed.
If it is in the public interest to have a new hospital, because the old one is Victorian and not fit for purpose by modern standards, then if PFI delivers a new hospital, is it not serving the public interest?
The fact that the government will be paying for it on the never-never forever is immaterial to those who need the service today.
It's all swings and roundabouts. If the government had not done PFIs, and issued more bonds (i.e. increased whatever the PSBR is called this week), then they would still have to replay those bonds. Further, issuing too many bonds raises the public debt to unsustainable levels. With PFIs, they do not borrow the money themselves, yet the payments are still due under the contracts for the service being provided. But these come out of a different "bucket", so all is good. Apparently.
I'm not a very good devil's advocate!