And also - I didn't say that everyone was meant to be a manager. I said that a school with equivalent demographics in the UK would have parents possibly doing skilled / managerial / professional type jobs.
In many European countries, a plumber IS a skilled trade that takes years of apprenticeship to do (in Germany, approximately 3 years), with a very demanding "Master", and numerous exams along the way. I haven't encountered many "cowboy builders", etc. over there. Just watch the Grand Designs episode with the German builders versus the British suppliers - it made a complete joke of the Brits, who arrived ridiculously late considering the very low mileage they were travelling, and delayed the Germans' work! In fact, you're likely to find better tradesmen on the black market over there than what you find on the proper market over here.
Those apprenticeships are quite difficult, and not well-paid. You have to cope with an often overbearing Master - you get screamed at half the time. From the Master's point of view, the teen has to earn his respect. In contrast, teenagers over here often leave a job, if they believe they are not shown any respect. How "skilled" can you possibly become that way?!?
Most people can speak basic English (or better) in ther European countries, too. You can go to a petrol station, and the person behind the counter will speak to you in English, if you so wish. I just don't think that a lot of the people you think are "working class" in these other European countries are the same as some of those in the same category over here. They are likely to be better educated, even if it's not academically, but certainly vocationally - which results in a sense of pride in one's work, and more respect for what you do. Some of those you see as "working class" over here, would probably be more like an "underclass" in other countries.
Population density is larger in the UK - you'll find there are a lot less people in Finland! The more people there are, the less homogeneous the country's society is likely to be, i.e. more people = more disparity.