As long as the AUMF exists and is in effect, it is both legally and effectively the role of the President to act under its grant of authority in accordance with its purpose.
Nah, this bullet is an off the wall insane interpretation of the AUMF. They were 100% right to mock you for it. Not to mention that the AUMF is actually about September 11, and specifically textually so, not just in motivation. Did the Houthis plan, execute, or shelter those responsible? It's been a huge stretch to even use it how it's been used. It's not in any way, shape, or form a requirement to go fight other random Islamic groups, whether or not they deserve it.