I've had a heckuva time getting into the US, on multiple occasions spanning 23 years—detained multiple times, denied once, all pre-current era. This is with all correct paperwork, honesty, no record of any kind, zero drugs, etc. There are other reasons some folks are sometimes denied; the concerns held by those facing the crossing are valid. Highly likely the Canadian forum people will get in, but after my awful experiences I would always have a back up plan (a way to get home from the border if needed, etc). I too am more concerned now.
tl;dr: KMMK, Jon_Snow, etc, you're not crazy! Have a back-up plan in case needed, and otherwise enjoy :)