Earlier quoted context omitted.
You might be making the assumption that the US wants to make the process easier.
Not to defend the US immigration system, but my experience is that this user-hostile behavior (modulo the port scanning lol) is endemic across US government websites - including those that nominally want to serve you, those that are at the state level instead of the federal level (such as the DMV sites), and those that are even internal for use by government employees only. It's bad enough that in some cases I believ…
Obama had the Digital Service (that Trump shut down) which paid higher salaries. Those folks were sharp and everything they touched was actually decent.
As I noted this is not unique to government. Large corporate projects at the Fortune 500 are often the same sort of consultant-driven crap.