I think taking on debt for education is a sensible financial decision. But the level of the debt that is sensible must be considered.
When I went to college (too long ago) it was expensive, but not nearly as expensive as it is now (in the USA at least – I am not as familiar with the costs outside the USA other than knowing in many places that university education costs are very reasonable).
I don’t have any hard cutoff where I think taking on debt no longer makes sense. But I do think I would include cost as a major factor when deciding what college to attend if I were facing that decision today. From a personal finance perspective I would only consider my debt or the spending of my savings.
If my parents or the school or someone else want to pay for a large portion of the the costs that is wonderful. I do believe the expensive and highly rated schools provide a great education and great benefit. If I were a parent that was well off I would have no problem paying the very high costs if I could afford it (which would mean I was far ahead on reaching financial independence).
The costs of college in the USA are so huge now that it may well be wiser to find a less expensive school in order to create the best personal financial base as a young adult.
The huge costs also mean I think it is much more important to take into account the likely financial picture after one graduates. It is much different to go into debt for a engineering or math degree than one with much lower expected salaries (Engineering Graduates Earned a Return on Their Investment In Education of 21%).
As I wrote on my other blog: In the USA More Education is Highly Correlated with More Wealth.
As I have said before the reason to chose a career is because that is the work you love, but in choosing between several possible careers it may be sensible to consider the likely economic results. And in choosing how much to spend on your education considering your future earnings is wise.