This is true, but largly in TeX and only Parts of it in LaTeX is still LaTeX. But you're right, I did use only a few rudimentary features.
I think this is the minority view of LaTeX: it's built on top of and is a subset of TeX, not a superset. No one would ever consider \def to be LaTeX for example.
Not to denigrate what you produced of course.
I've always thought of LaTeX as more of a superset, but I see where you are coming at (I've read the TeXbook)