discuss.answer
It's possible that the inline tpl with the [[+content]] placeholder is the problem. Try using a chunk tpl instead.
Actually if you think about it it's logical. That is itself a tpl, being processed by the parent getResources snippet. So what does happen to a placeholder in a tpl? It gets replaced with its value. So you can't have an inline tpl with a placeholder in the child getResources call. Before the child getResources call was run, that placeholder was replaced with the content of that child resource. No wonder the poor thing couldn't produce anything.