No one is going to look at this and think, "wow the US is no longer willing or able to defend naval shipping." In fact the commencement of the operation is pret

No one is going to look at this and think, "wow the US is no longer willing or able to defend naval shipping." In fact the commencement of the operation is pretty clear indication that they are doing exactly that. The Houthis in this case are closer to kids throwing rocks at cars than a viable military force. Bringing the SWAT team to rain terror on the whole neighborhood is, as you say, likely not the best course of action.