Can't you just marvel at the achievement without worrying whether celebrating this could be seen as taking something away from somebody else?
Personally I don't care much who was first. There were others roughly around the same time trying similar things. It's the same with "who invented the airplane" and "who invented radio". Many countries lay claim to having been the first to do X or Y. I don't care much and I don't think anybody else should.
Zuse built an amazing machine. Does that not warrant a bit of respect? Add that he had no help from the government or any big company. Does that still not warrant a bit of respect?
In my life I have "invented" quite a few algorithms that later turned out to be an old hat because smarter people had already invented them years or even decades earlier. To me that does not take away from my achievement :-)
It's not important whether you are the first one to achieve something. It is important that you achieved it.