And yet, many people I know who have immigrated here, whether on work or student visas, have had no issues at the border.

So.... I'm not sure what to tell you. What exact treatment happened? Somebody being rude to you at the border doesn't count, who cares about that? If you were detained, or interrogated, or something along those lines, then yeah you have a legitimate gripe. But I don't want to hear anything about "the security officer was rude".