I disagree with your post for two reasons:
(1) What you seem to be saying is that a court should do what is best (or, more accurately, what you think is best). This runs very counter to the traditional, conservative notion that the Court should be applying the law, for better or worse.
(2) By their very nature, asylum cases often have to be pursued stealthily. A person who is truly persecuted and fears for his or her life can't reasonably be expected to openly stroll up to a legal point of entry. That is why the law in most countries provides that asylum is available no matter how the applicant enters. Of course, as Deez pointed out, asylum shouldn't be granted if there is no basis for it -- but that's not the same as prohibiting an application in the first place.
True conservatives on the Supreme Court (Roberts, Cavanaugh, maybe Alito, and maybe Gorsuch) will uphold this decision by the Ninth Circuit. Results-oriented fake-conservatives (especially Thomas, but to a lesser extent Alito and Gorsuch) will vote to overturn the Ninth Circuit.