Because naming things is one of the two hard problems in computer science — the other being cache invalidation and off-by-one errors.
More seriously: Tesseract (the 4D hypercube) felt right for a tool that adds a dimension to how you see architecture. And if you've seen Interstellar, there's a scene where the tesseract reveals the hidden structure behind everything — that's basically what this does for your codebase.
I was aware of the OCR library but figured a 40-year-old project can share its name with a newcomer. No one's going to accidentally npm install their way into a 3D architecture editor.