The act itself does not make a mass murder/shooting a terrorist act. You also need to have political intentions. If someone is insane and incapable of understanding what they are doing that's not terrorism. If someone is killing for personal reasons, that's usually not terrorism either until they ally themselves with a political movement and seek to gain political goals.
I'm assuming you're statement about toddlers is in reference to the Sandy Hook shooting? The shooter was Adam Lanza who had a long history of autism and mental health issues. He was also diagnosed with Aspergers, OCD, anorexia, and potentially schizophrenia. He had sensory issues that made exposure to every noises and lights torture. It was a tragedy that someone with all of those issues was allowed access to weapons. However, as Lanza had no political motive, it was not terrorism.
Refusing to describe Lanza as a terrorist has nothing to do with racism. I don't know why you can't seem to grasp this concept. It's been explained to you several times. The issues surrounding Sandy Hook have to do with mental health and gun control. Whereas terrorism is a political force that has to be dealt with differently. Dealing with terrorism involves disrupting networks that provide support and funds. Hence, the separate legal designation.