This very much depends on what you define as a real job. To some extent I agree with your contention, Modeller, in that I feel we would all benefit were our MPs less Westminster orientated and have more experience in the real world; I have thought for instance, that we should consider a minimum age restriction on MPs so we at least get MPs who might have some life experience like raising a family and so on.
But I do not think this "very few if any" comment of yours is quite right. A recent study looked at the backgrounds of the 650 MPs and concluded that only 90 had no discernible work experience outside of politics.
And age does not automatically confer respect. As a kid, I still remember taking the mickey out of some of our older teachers far more than the younger ones. What garners respect is the ability to communicate an enthusiasm for the subject being taught, and that is a quality irrespective of age.