"OMG we're the government and everything we do is huge and unprecedented so it is impossible for us to use off-the-shelf anything and we can learn nothing from best practises" is step 0 of every failed big government project.
There's significant thawing of that attitude (and gov.uk, for their imperfections, is definitely a very positive part of the trend) but the idea is alive and well.
Yes because a real world organization with IT systems going back 50+ years is exactly like some me to macbook and MBA start up with two men and a pantomime horse in old street.
There's significant thawing of that attitude (and gov.uk, for their imperfections, is definitely a very positive part of the trend) but the idea is alive and well.