Well, I'm sorry that Monolith Soft couldn't read your mind to find out you, personally, don't consider high power a noteworthy attribute.
Just watch as they make Smash Flare a canon move in the next game they make featuring her.
Okay, insult aside, I'm not sure you're getting the whole point. A strong f-smash, isn't particularly special. Dr. Mario has one of the strongest forward smashes in the game, but you don't really hear people talk about it much. We know Pyra is stronger. She's a strong fighter with strong moves. Again, that's like pointing and Ganondorf and saying his power is a gimmick. No, those are his attributes. That's just how he is. Conversely, it'd be like if they said Mythra's gimmick was having a fast smash attack. And, if they take the burst damage as Pyra's thing, fine, but that doesn't really fit as a gimmick, at least how they did it. Being strong or fast is not a gimmick. I know Pyra didn't really have anything like Foresight, so they either could have just said, "yeah, she's strong but doesn't really have her own gimmick" or they could have made something up. An f-smash is not a gimmick even if they want you to think it is for some reason. Or, if they still wanted to go with it, actually at least give it a distinction as strongest. Not like it isn't slow anyway. Even then, probably shouldn't get it's own tab on the moveset list. Take a look at those. Most if not all of them are for somewhat unconventional moves or mechanics.
Flare Smash just really isn't that special, yet they hyped it up. Why claim a gimmick that isn't really a gimmick? For symmetry? Does she need one? Not necessarily maybe, but, come on, if you don't have something just admit it.