Whenever you hear a faith-head exclaim, "This is incredible! It's a miracle!" what s/he's actually blurting is, "Hallelujah, this is really so incredible! But I'm just too stupid/lazy to hypothesize/understand/explain/know how it could've happened otherwise." Such people don't bother to calm down, take a piece of paper and write down various possible parsimonious explanations, test them, rule them out, before concluding, "I've checked a huge number of plausible naturalistic hypotheses and none of them can explain the phenomenon. Therefore, the supernatural hypothesis remains a candidate. Notwithstanding, since it is fallacious to make an argument from ignorance, the actual cause cannot (by default) be said to be supernatural, since only if we come to ultimately possess omniscience of the totality of the natural world and exhausted all possible naturalistic explanations can we conclude that the event was in fact supernaturally caused and thus indeed a miracle. Since such omniscience is not at all forthcoming, no inexplicable event/phenomenon now or in the future can ever be known or said to be a miracle All we can say is that 'We as yet cannot explain it. We just don't know.'"
Miracle-mongers have such puffed-up egos and warped minds that when they're ignorant of how something came about they conclude they know it must've been supernaturally caused. As others have said "God did it" and "it's supernatural" are mere placeholders for "ignorance."