First of all, I suppose geeky language in an email to developers is not wrong, but I don't see much geeky language there anyway. And I find your responses more arrogant than the text they adress (Duh!). All the examples you stated use names right beside the icons or at least in a form of mouse-over hovertext. Or give you the option to chose. The text hovering over avatar's head is there for a purpose. Try turning it off in your preference window and try to move between people who change their appearance often. Try to find a contact icon for a person you need to IM now, when they change their profile picture once a week. Even with hovertext... would you like to hover your mouse over 100 icons to find the person you want to interact with?
And yahoo also shows names next to user icons.

You use the word "geek" almost as an insult. Again, this is software developers' talk, they don't hire people who are not "geeks". I won't comment on "the weening need to be right". It's not about trying to convince you you should learn 136463552846452 commands and go Linux, because it's safe for your PC & your work. It's trying to tell you that placing stickers next to the phone numbers in the contact book that you keep next to your phone instead of writing down the names is not a very good idea. And it doesn't take a complete nerd to figure that out. It's in plain sight.