[mumblemumble]

> DI is the removal of complication when it is done correctly.

Personally, I would rephrase that as, "DI is a pattern that is designed to mitigate certain kinds of complexity when done correctly."

That leaves room for two ways in which it can backfire. Doing it wrong, like you say, but also doing it in situations where you don't actually have one of the problems it's trying to solve. Cost/benefit ratios always get out of whack when there's no benefit to offset the cost.

[eropple]

That is a fair edit, for sure. Many systems don't need a formal DI mechanism, though should they scale to a certain human-size they'll probably invent enough of one anyway just through composition (if they don't collapse into a ball of mud).