Saudi Arabia is a Sunni theocracy and doesn't want them to do this, so they give weapons and money to their Sunni opponents.
Understatement of the year. The Saudis ran a multi year bombing campaign that killed tens of thousands of civilians, with direct US support (including mid-air refueling and “targeting”). On top of that, the Saudi/US coalition created a famine via blockade that likely starved 50k children to death. Were the Houthis backed by Iran? Sure. Were the Saudis and their former puppet government in the capital not backed by the US? And they still lost.
https://news.ycombinator.com/newsguidelines.html
Edit: it looks like you've been using HN primarily for political and ideological battle. We ban accounts that do this (regardless of what they're battling for or against (see https://hn.algolia.com/?sort=byDate&dateRange=all&type=comme... for past explanations about why). If you keep this up, we're going to have to ban you, so it would be good if you'd review the intended spirit of the site and fix this.
So I guess they're genociders, and they're bad for business.