I agree with your points on RE0
@Jonipoon. In my own headcanon, I've basically excluded the game's story from the timeline of RE. It just doesn't fit in as a prequel.
There’s quite a few missed opportunities within this series but I'd say the game with the most glaring ones is RE6.
For me, it is a composite of intriguing and endearing ideas (along with some sh*te ones) that were horribly executed.
From the poorly constructed character mashups to the underwhelming villains used. Their decisions were just plain
bad and it lead to Capcom drastically uprooting the series without any thought on the loose ends they left for previous characters.
Another missed opportunity was a proper follow up to REvelations 2’s story. I know I’ve harped on about this one too but it’s story and villain would have been perfect to incorporate into the main games’ storyline.