C'mon, an AT&T underling is handing along advice on what Steve Jobs should wear? I work for a MegaSlowGiantNotWithItCorp, and the people on top aren't stupid. They pretend to be when they can get away with it, but they aren't really. Plus, matters of personality, protocol, and diplomacy are where they shine. The people attending to the AT&T executives probably memorized the names, ages, and favorite sports of Steve Jobs' kids just in case they had a chance to chat with him. They would have, um, kind of known that he was a notoriously finicky control freak and narcissist with an aversion to suits. (You know this, yet you assume that someone whose job it is to know this, and who has finagled themselves into a position working with high-level executives at one of the biggest companies in the world, would somehow not know this?)

Perhaps as a matter of diplomacy, just to get under his skin, they decided to insult him or pull rank on him ("my market cap is bigger than yours"), but they certainly didn't do it on accident. And honestly I can't imagine them needing to invent ways to get under his skin when there are so many contentious issues on the table.

Even back at Dell in the early 1990s there was some friction between sales/marketing managers and engineers

That's the difference between being an engineer and being one of the most powerful and respected CEOs in the industry.

Plus, the 1990s were a lonnnggggg time ago. The bestsellers about the casual tech company culture of the early 2000s are already in the remainder bin, because they've achieved cliché status. If you think the executives at AT&T missed all that, well, it would have been impossible for them to miss it, because they were shopping at Barnes and Noble and watching CNN just like the rest of us.