Graham, lots of the delays are caused because the silt charts don't add up and crazy decisions are made to take out cash - this creates delay.
You are of course right that changing reqts causes havoc - but they still need to be set properly and managed and accepted. OK, get contractors to do it, but how are you going to effectively control those contractors given 1000s of diverse and dissimilar projects? Trust the goco as they have the skills? lol!
ignoring past mod woes for a moment, is there a vision for what govt oversight would be on e.g. a typical project?