With between 8000-10000 to choose from, it does not matter if they loose what you consider to be potentially good pilots. This is not a 9-5 job managing at tescos, the Armed Forces recruit individuals willing to give far more than their time if the job requires it. besides, there are plenty of kids out there begging to get in, and do what they consider to be their dream job. So why waste money on incentivising recruitment when we have thousands willing to go through the faff of selection?
If you are unsure of the length of service, or know anyone who at the application stage is unwilling to do this period of service, I would suggest this job will not be for them.