Yes, but Konrad Zuse was driven to do his early computers by the tedium of doing arithmetic by hand in his engineering bureau. So we would have gotten computers anyway.

Yes and no. It is true that Zuse's early work, starting in 1936, was done on his own and (I will grant) motivated by non-military calculations. But that early work was on a purely mechanical computer, like the analytical engine and the difference engine of Charles Babbage -- and no mechanical designs were ever realized (except much later as part of the "retrocomputing" movement when their computing capabilities were no longer needed). By the time Zuse started incorporating electrical relays into his designs, in 1939, he was a member of the German military. It looks like he might have left the German military before the end of the Nazi era, but that matters little because the whole of German society was organized around military needs and military goals.

More importantly, the argument that "we would have gotten X anyways" can be applied to almost any technological development. Speed of development is important, however, even if all you care about is whether humans reach a certain level of development eventually (because the longer it takes to reach that level, the greater the chance that one of many potential catastrophes causes humans to die out or to lose the ability to invent the radically new technologies).