I had to interview someone yesterday for a developer role, and the discussion inevitably got round to BizTalk. He was rather argumentative, which made the BizTalk discussion particularly frustrating, as he kept insisting that BizTalk was a very easy product to understand. I think precisely the opposite, since the impact of a BizTalk implementation within an organisation can be extremely complex, and the move to a message-based architecture is significant, to say the least.
I think the confusion lies in Microsoft's classic 'easy-to-use' philosophy, which serves the developer community so well, but which can often lead to people overestimating their own abilities. Yes, creating an XSD in the schema designer is easy. So is creating a map, or even an orchestration. Developing and deploying artefacts into the environment is just drag'n'drop. How hard can it be?
Understanding the underlying architecture and being able to use it to its best advantage and in the most appropriate manner is anything but easy, and to my mind, if you meet someone who thinks implementing BizTalk is simple, they probably don't understand what they're doing.