Have to agree with LoveToKill, when formulating battleplans, typing would be a real waste of time during a battle. And especially with 2v2 and bigger battles, or guildwar battles, you don't have time to keep typing or it will cost you units. Voice chat would be a lot more practical in those situations.
"The flower of friendship blooms even in hell. On the sand where waves come and go, it leaves its petal as a memento. We will make it bloom again someday, The Okama Way!" - Mister 2, Bon Clay