I look at this from a slightly different point of view as I have personal experience of a situation that, while different to the one highlighted (which has my spider sense tingling with the 15 years hiatus and all the back and forth travel but who knows), would have fallen foul to the rules.
I was working abroad (for a British company) virtually all of my twenties. I am fluent in the language of the country I was working in and while there met and married. As I spoke her language my wife never learnt English and eventually I was moved back to the UK when the contract was ended - these things happen quickly in the oil industry.
Of course, since we have been back my wife now speaks English and has passed the Life in the UK test and so on but what would have happened had this rule been in place? Say it took my wife 6 months to learn English to a suitable level, would I have had to be separated from my family for 6 months whilst she learns English? We had an infant son at the time and I wouldn't really have liked to miss those six months. I could have left my job and tried to stay there but that wasn't really an option as it would have meant visa problems for me (I sometimes wish our immigration laws simply mirrored those of the country the immigrant was applying from).
By all means give people a year (or whatever) to learn English after they arrive here but I don't think not speaking English should be a barrier for initial entry.
Had the language requirement been in place at the time you returned to Britain might you and Mrs norman have prepared for it?
It *is* a precaution but not a satisfactory one. It does at least put a bit more responsibility for getting by in Britain onto immigrants coming here. But it really only treats a symptom rather than a cause - there is no encouragement to integrate and plenty of discouragement. You could seriously help that along without a State authorised language requirement by simply not providing taxpayer funded translation services.
Stopping Government translation services would boost the private economy for both translating english into foreign languages and for tutoring immigrants in english. The language requirement is the State saying 'you must do this'. Stopping the translating of all kinds of things into all manner of languages would be the State saying 'we will no longer do this' which is a cheaper and less authoritarian way.