I'm beginning to believe a lot people confuse "character becomes more badass" with a "character arc."
I would like to see the term badass stricken from the English lexicon. The connotation has such a low-brow fast and furious ring to it. It holds no value when describing a legitimate cinematic character. Those who coin it have no understanding of film critique.
Replying to @AdamLanceGarcia
I'm inclined to agree that characters becoming stronger do not always correlate with characters having arcs. I've seen characters who do not become physically stronger but still have arcs. And on that note, I find that characters can be strong even without physical power.