They did not account for the mixed feelings of relief your loved one is home, resentment they have a hard time acclimating to being home, and jumping right back into familyhood would be a process ... a very long process. Right when you get it to where you want it to be, another deployment happens.
Military families are in a constant state of adjustment. If you, a loved one or friend, find the welcome home is not all it's cracked up to be, help is available. Military One Source is an excellent resource. Tricare allows for up to eight sessions for military dependents to see a mental health professional without needing a referral.
Many MTFs (military treatment facilities) will authorize the active duty member to be seen off base due to limited availability of service and many prior military providers are now civilians, ready and willing to help. Chaplains and Military Family Life Consultants are available on base. Setting realistic expectations for homecomings will help as well.