Yep. GCHQ was recruiting on our CS course and the starting pay they offered was within £30-35k range. Working for literally any IT company in the region would pay more.
(obviously there are perks working for the government that the private industry cannot match, so for some people lower pay is acceptable)
Don't forget the (massive) tax benefits as government employee. To get the same net amount at the end of the month, in Germany you would have to make several thousand € more per year in the private sector.
In the end, you are still right but it's still a factor.
Not only that, but the senior technical role they hire for, Lead Software Engineer, maxes out at £56,984. I know a handful of people who've gone from GCHQ to my company, and they seem satisfied with forgoing the government pension in exchange for tripling their salary.
I think the problem is that the civil service / defence industry think that technical "boffins" are some sort of cheery working class NCO who will work for tuppence ha'penny. the type who be played in the films by Normal Wisdom or George Formby
"mr Oldfield, that Kims a wrong un - I saw him taking money from the from the orphans fund"
(obviously there are perks working for the government that the private industry cannot match, so for some people lower pay is acceptable)