There are multiple problems with requiring a degree from a pilot:
- Higher education isn't free in many countries and requiring this would just put more debt to be paid off on top of pilot training cost (in case of the UK student loan system), or create an even higher financial barrier to this profession, where a loan/state-sponsored education system is not an option.
- There is no demonstrable case to be made that a pilot with a degree is a safer one. Time studying a technical subject (say how much would a double PhD in chemistry help the pilot in dealing with an emergency?) would be better spend to in-depth studying of aviation subjects, or even better - hands on flying, such as UPRT et al.
- Degrees tend to take at least 3 years of studying full-time, which means at least 3 years without any serious income and reduced earning ability for 3 years, with effective mandatory retirement age of 65. That doesn't seem fair.