Yeah, I mostly play tanks when I queue for QM, and even for me the wait times went up to 5+ minutes, so I can’t imagine what it was for assassins. Some of that is not only do they have to find 2 tanks, but they need to be close to the same MMR. If they want to keep the queue times short, they have to grab any old tanks to fill, and I can assure you matching a Bronze tank to a Plat tank isn’t fun for anyone.
But hey, hopefully you can find some buddies who enjoy meatshielding or swearing at the computer screen while trying to keep a suicidal Greymane alive! 