Not believing in something is not in itself a belief or a philosophy: it is the 'ism' at the end that tends to cause the trouble. Both atheists and believers can be as arrogant and witless as each other in frustrated debate, and people may choose strong and unapologetic words to raise awareness of the agenda. But despite the name-calling, it is still a fair point that to not believe in God is no more a 'belief in itself' than to not believe in the Loch Ness Monster, Poseidon or anything else one might personally consider far-fetched. Beyond that, there is only how you choose to express yourself.