The sad thing is I don't see the public sector getting any better at this anytime soon.
However (at least in the few governemnt bids I've been involved in) if the low bidder does not get the award, they can challenge the award and often do. Then the government has to defend their decision and give the reasons the low bid was disqualified.
Good luck with that. It is prejudiced discrimination because you assume that if the bidder never did a contract like what you're looking for, they will not be able to do it.
It would be just like you don't want to hire a junior because they never worked before :)