People aren't staying in as long - the career profile is changing radically, so is that 45/10 figure as relevent to someone in their 20s or 30s as it may have been 25 years ago I wonder? Another complication is AFPS is paid for by general taxation and has to fund the Armed Forces Compensation Scheme, which is far more generous than it has been in the past. That particular demand on AFPS coffers is going to soar over the next 30 years and its a hidden cost of the scheme that tends to get forgotten.
You could argue that the need to be pragmatic is stronger than it is with other sectors of the public pension world. The MoD pays 37% or so of officers' salaries and 21% of salaries for ORs into the scheme, rising to (on average) 34% over the next three years. So, does it want people staying in as long as before? Probably not..? Thankfully (for the MoD), most people seem happy to serve fewer and fewer years (hence my first point).