Sounds like god damn purgatory to me. If you need to reassure someone that you're not bullshitting them every sentence, there's probably a serious problem you need to address first.

Yes, exactly. Obviously you need to pay attention to the genre you're writing in, and use your discretion when determining when first or third person would be better. But the "never use I" rule takes away that discretion and replaces it with an inviolable rule that quite often doesn't fit the situation.