Except you don't have to take the lowest bidder but the best. In this instance the Scottish Government desperately wanted to not take the Anglian Water bid - if they could have pointed out the bid was infeasibly low, or that Anglian had a track record of the behaviours you mention, or other benefits that the public sector offer might have then they could have avoided giving it to Anglian. Despite trying several times to make the Scottish Water bid better they still couldn't beat the private sector alternative.
