>piano is extremely important to Kris
>looks distraught when he can't play it in front of Susie in chapter 2
>one of the first thing he does when he's free of (You) is play the piano
>bonds with Susie over the piano
>his opionion of Ralsei improves if Ralsei compliments his piano skills
And now look at his home situation
>no piano at home, not even a cheap upright none
>not even a synth keyboard anywhere in sight
>had to play it at Noelle's house or at the hospital instead
>had to learn it from the Internet instead of taking classes
This is, in my opinion, the biggest condemnation of Toriel as mother.