What has otaku culture to do with that? As at its core everyone that is really ionate and spends a lot of money and time for his hobby is an otaku. (Albeit the word is more derogatory than the Nerd and geek equivalent in English and west.)

So someone that has a large collection of model railway would also be an Otaku.

So that automatically means that all previously ones did not love anyone. Not Thier loved ones, nor children, nor best friends, not siblings, etc.

The only explanation I would have is that she awakened it as she truly beloved that Boruto has turned evil which is traumatic. (Even so not quit accepting it.)