I think I might be like your wife. For me, it's not so much that I'm too busy (although, if I am busy, that adds to my annoyance). It's that I'm deeply uncomfortable on the phone. It's not like a phobia; it's just this weird sense of displacement and inability to function over the phone like other people do. I feel like I'm trying to listen to sign language. So for me, the phone is a tool to take care of business and then be done.
I miss my husband when he's gone, but talking on the phone does not help that. It would be like if you were thirsty, and I said, "Eat this apple! It's delicious!" and you said, "But I'm thirsty, not hungry," and I said, "But it's organic! And home-grown!" It's probably not that she doesn't miss you; it's probably that talking on the phone does not fulfill the same needs that it does for you.
I talk on the phone with my husband when he's gone because I know he misses me and does get something out of phone chit-chat, but I'm always relieved and a little tired, even, when we hang up. I have a lot of trouble carrying a conversation with him (or almost anyone except the extremely chatty people), no matter how much I try, and it's awkward and stilted, even though we've been married 10 years. I like to know he's arrived safely, I like to know if he's having a good time or not, and I like to know when he leaves. I would be perfectly happy if he texted or emailed these things to me, though.