G-d or God?

[catholic_heart]

Hey, I've noticed that several people in this and other communities, when referring to God, omit the middle vowel. My assumption has always been that this is a mimick of the Jewish practice of removing the vowels from Yahweh and thus writing God's name as YHWH. I'm wondering why people do it with God? In the case of YHWH it is an attempt to prevent the defiling of God's name. In the case of God, God is not a name; it is an indication that there are not many gods, but rather only one God, and thus sets He whom we worship as singular among the many non-deities, gods, worshiped by others. But Yahweh does not translate as God; it translates as "I AM WHO AM."

So, and this is only out of curiosity, and know that regardless I respect your reasons for doing it, but if God is not actually a proper name, why omit the vowel?

Peace!