Interesting thread.
Throughout my short time involved in aviation I have seen quite a few early 20s embark on commercial training with only school qualifications and no real prior working experience. I think at that age there is this feeling of 'I will be a pilot no matter what' However, I believe it is worthwhile gaining a non-flying related qualification and subsequently getting a few years working experience under your belt.
I agree that there has to be a sensible degree choice with good opportunity to gain employment, and times are no doubt harder these days on the graduate recruitment front. I know of one engineering firm who had over 1200 applicants for 18 graduate posts, the starting salary on offer for graduates was £35k. Although. as per previous posts you will find investment bankers, consultants etc with a wide variety of degrees so a particular degree does not necessarily pigeon-hole the individual. Whereas a CPL/IR can in most cases only be applied in one field. Therefore it is a bit of risk embarking on commercial flight training without any real back-up career / experience.
Once established one can then follow the modular route keeping risk as low as reasonably practical. There is always that risk that one will become comfortable in their current career, good salary, benefits, work/life balance etc and with the current economic problems and news of constantly declining terms and conditions in the airline industry it can become a difficult choice, but at least a choice exists.
There is no right or wrong way of doing it so this is merely my humble opinion.