This is one of those cases where both sides have some insight depending on viewpoint. The OSI model is like every other model. It isn't reality (at least in TCP/IP) but instead is a helpful abstraction esp. around troubleshooting and understanding networking concepts. There comes a point where the model breaks down but that doesn't mean it's an unhelpful model just that it isn't a complete picture. I try and work networking problems through the OSI layer model but am aware when things don't really fit well into it (MPLS, MSS, ARP, Layer 5-7).