It had the unfortunate distinction of releasing after the Switch was already popular and the 3DS was already dying down. Critical and fan reviews are pretty good and there's no real negativity geared towards the game in general, so it's not a big leap to think that it would do better on other, more accessible platforms.
That is exactly what happened with Golden Sun Dark Dawn, as it was released right after the ads came out. The game series died after that, of course. Hmm... I wonder why they're remastering it...
I personally loved it. There were aspects I'd change, like the story just ending right after you beat the final boss, and the fact that there is no difficulty adjuster.
All right, all right, Mr. Amazing Scienceman. Clearly, your fantasy world is doing a fine job of making you happy... -Janne Angard