3 simple points to end the discussion with any Sunni/Shiite

[Angrboda]

No Sunni or Shiite is going to accept ignoring the hadith as a ground rule, so this advice is pointless.  As for the rest, just as you do, they simply point their fingers elsewhere.  Do you not learn anything from your own behavior?

Here's the whole point: the Hadith books were never held as a revelation from God; rather they are "the recording of Mohammed's sayings after more than a century after his death".

All Muslims believe 100% that the Quran is the word of God, it's the special case. But the Hadith is not.
A person who wants to resort to Hadiths, is a person who is resorting to man's word, with the admission of all Muslims.

Professional tip: the Quran isn't from God either. (And for what it's worth, the Quran states that Mohammed's conduct is an example of right belief, so indirectly it does sanction the hadith.)