Though, in terms of the title, letting go of spite, i don't see the author really talk about that. Beyond just, yeah this happened to me, and now I want to try to let go of spite.
The last paragraph touches on that:
> I’m now writing this in an attempt to start letting go of that spite. Just like I was during school, those teachers too were probably doing their best, and making mistakes, as we all do. Instead, I thank them for trying, I thank them for their patience. I know I derailed nearly every class and I know that many of you at least recognised the potential, and tried to get me to see what I was capable of. But the truth is, the format of traditional schooling just didn’t work for me. And I now know why. But, I found my path eventually, and continue to do so.
I would redefine that as 'Life'.
The only way to produce "perfect" human beings is to put them into a sterile environment where you literally control everything about it and then you have the issue of homogeneity.
To live is to risk, for many "classic schooling" is very beneficial, for many it is not. I'm not advocating doing absolutely nothing because nothing is unknowable, I'm just pointing out that there is no such thing as a perfect solution.