I suspect that my collegues are being unfair both to the US educational system and to those dedicated officers that work all day then study hard at home for many years to attain the Masters needed to advance beyond Major.
In the 80s the RAF was attempting to recruit about 1/3 of it's officers from the graduate population. Don't know it it achieved this. What you actually need to consider are the pros and cons of having a degree in the RAF, not whether all your mates will have one. On the plus side you will probably join as a more rounded individual and so increase your chances of surviving the training; it also gives you a fall back career if you don't. On the downside, you are a more rounded individual mainly because you are three years older than non-grads. This is not a problem in training, but those extra years will work to your disadvantage downstream if you intend to run the joint; the military can become quite ageist when it comes to promotion and command tours.
If you are tempted by the "In Service Degree" (an OU course), think very carefully about whether you will actually have the time and opportunity to study once in productive service.