While it may be highly unusual on an annual basis, we've been within one game of doing it two years in a row now, and had Miami come to our place, that would have likely been our win and undefeated MAC season, not theirs. Luck of scheduling in their favor. Also, as you say, yes, they were highly lucky in about eight games. Context matters.
So do hypotheticals. As you said before, it's necessary when there are only about 35 at-large slots for 300+ teams. Justifying Miami's entry on WAB is almost as weak as their schedule.