Lua is single pass too and doesn’t have the same restrictions.

Wirth is also from a time when resources were incredibly constrained. So it was a combination of his ideas for what a PL should be: easy to understand, easy to learn, powerful enough to do everything he needed. And the compiler for the language also needed to be the same.

Unfortunately he got kinda stuck in that, and you can see it in all the Oberon flavors: he was clearly fighting against the limitations he imposed, but couldn't break out if them.