I think its more like pretending that things are simple (or that a simple solution is enough), when in truth some things just aren't simple and pretending otherwise is unwise. Like how they ended up adding a package manager later on, which of course was never part of the initial design because they thought nobody needs to version their dependencies. Or how they ended up adding generics later on, because they thought nobody will ever need to do "abstract things".

The problem is if you don't consider these things in your initial design, the solution you end up with later tend to be worse.