Arguing with your co-workers isn’t a bad thing. It’s not creating a negative work environment — it’s a tool to help you make good decisions. Being an empty cheerleader and telling everyone that their idea is great is harmful and short-sighted. Argue and make good decisions.
Product design at GitHub by Kyle Neath is a good read.
I believe modern company culture should encourage arguments. When done with respect to fellow co-workers, arguing makes you leaner and avoids half baked decisions. Too often talented companies fall apart by aiming for mediocracy.