stable conditions

Hi, I'm a 25 year active duty Navy CWO that just received PEB findings. I got proposed ratings from the PEB of 90%DOD and 100% VA and to be put on the TDRL. My unfitting conditions are 70% MH, 50% Migraines, 40% lumbar spine DDD/spondylolisthesis and 30% cervicalgia/DDD. My question is why...