My fwh travels a lot for work, and often feels the way you do. He wants me to be more excited and happy when he gets home from his trips and it saddens him when I'm not.
From my point of view, while I DO love him, and AM happy he's home, sometimes it's just the intensity of his physical presence that brings on a slight trigger and makes it difficult to give him the happy, bubbly welcome he's looking for. Over text, email, etc there's a little more distance which can make it easier to put thoughts of the A aside and let my love and emotion for him show.
I hope you guys can work through this. Have you talked to him about it? Maybe not a great idea to approach it from the aspect of criticizing how he currently reacts (if is it due to a trigger response of some sort, I just don't think criticizing him for it is the way to go right away) but maybe just letting him know how happy you are to get home and see him, and how much his positive reactions mean to you (welcome home hugs, etc). Kind of reinforcing his "positive" behavior, you know?
There's also the possibility that maybe he's just having a hard time with things and wasn't able to share or express at over texts thru the day. When he sees you after work, those emotions may flood in and stop him from acting happy to see you, even if he really is.