Because they are massively, massively corrupt.
http://www.timesonline.co.uk/tol/comment/columnists/guest_co...
"For nine consecutive years the EU court of auditors has refused to sign off the budget. The numbers are huge. The annual EC budget is around ¤100 billion (£65 billion). The auditors cannot clear 95 per cent of that. We simply cannot tell what is happening to that money"
Or to put it another way, if this is true, it means that they are able to run real EC functions with just 5 billion Euro budget. That would quite efficient indeed.
My whole point was about low ranking civil servants that do the bulk of the nitty-gritty administration work and that all must pass through a highly selective competitive exams (1 in 29 applicants [1] cf. Harvard's 1 in 14 [2]).
And for these people, from my limited anecdotal evidence I got impression that they are indeed efficient, at least for bureaucracy standards.
For example, http://www.tfl.gov.uk/corporate/about-tfl/investorrelations/... shows that Transport for London (buses, trains and underground) alone employs about 18,000 people (and probably quite a bit higher now).
European Commission that basically runs European Union (500M people) has just around 25,000 employees [1].
This is tiny. Just to get an idea about the scale: New York City (8M people) government employs 250,000 people (though to be fair, I have no idea who is included in this total) [2].
EC seems to be doing something very right. They offer very good working conditions (pay, holidays, benefits, security), so they are able to attract good people. There is a tough competition for these civil servant jobs.
[1] http://en.wikipedia.org/wiki/European_Commission
[2] http://en.wikipedia.org/wiki/Government_of_New_York_City