It's not a complete answer, but you might like to see the FAQ section "Breakfast foods", with answers by /u/agentdcf, /u/Kalimah18, and /u/eggplnt. They discuss some factors that went into "traditional" American breakfast foods (like Mr. Bernays), but not why some might consider these foods unacceptable for other meals. (Also, these discussions are fairly old, so there's a lot of "fluff" by current AskHistorians rules.

This is not to discourage discussion. More questions, data and debate are welcome.