One possible philosophical answer:
The phrase 'taking the name of God in vain' may not have sense at all. Let's see... is it 'God' the name of God? hum... this is a theological problem... In fact, we don't know the name of the Christian /Catholic God - many philosophers consider Him the One about nothing can be said or known.
We use the concept God to refer to any kind of God, so it doesn't refer to one and just one - its a Concept not a Proper Name. So... it's impossible for some religious to use the name of God in vain because... they don't know He's name.
Its just a contradiction - but people don't see it :)