That does sometimes happen - investment does cause development. The mistake is to assume that's always what happens, and that everybody can benefit from the development.
The benefit is uncertain whenever anybody spends money on anything beyond survival. If you go around asking investors "are you using that money properly and beneficially", for consistency you also have to nag the poor with the same question. Should you put a bet on a horse? Is it really necessary that you visit anybody far away? What's the benefit in dyeing your hair? In both cases, you'd be enforcing arbitrary wisdom instead of acknowledging your fallibility.
Not quite. In some cases we’re certain there’s no benefit.
Oh I agree with you. I suspect it happens less than is the conventional wisdom, but I might be wrong.