I think the numbers speak for themselves. If the military is undermanned to the tune of 800 pilots then clearly the grass actually is greener on the other side. For some, life is good and they still enjoy the job, but clearly there are not enough people who enjoy it to keep the manning numbers balanced.
I don't see how things will improve in the future as the system seems geared now to work better for shorter engagement periods. I was always surprised how many students were already calculating their options and laying the ground work for their next job.
IMHO allowing pilots to switch to a reserve role would be a good start to help bridge the flow and maybe even encourage some people back. I would quite happily return for 3 days a week and supplement the reduced income with my own business, I'd even suck up some time on Q.
Otherwise, money does talk, but I don't think there is the appetite to offer a genuinely enticing FRI. The small amount they offered me to stay was less than one months salary in the job I took up after leaving. I'm sure there was some uptake, but if those people were staying anyway then its really money down the drain in terms of actually retaining people.