Interestingly enough, in the 'Open Source projects and poisonous people' talk[1] with two SVN developers, they mention how they chose that line specifically to make sure that everybody is on the same page with the scope of the project - improving upon what people knew and were used to instead of wild, new things. Specifically because they would often have people come into the community with some grand plans that would have just exploded the scope.
It is of course arguable to what extent there could be a general rule to this, but in this case, GIT is just so fundamentally and obviously the better option than SVN. Had somebody tried to make SVN into GIT, it would have simply killed SVN, so it was the right course of action to make it a new project. SVN was destined to die by its design.
To see the GIT adoption rates these days (particularly due to tools like GitHub) is very encouraging to people who like to think that sometimes, starting over fresh is the only option. Of course, the thing you want to build really has to be that much better than the old thing you're trying to replace.
So I agree with you - it's alright to say that GIT is better than SVN. The crucial point to me, though, is that it is so much better. So much better that it is worth the effor to build and worth the effort of the community to switch.
[0] https://www.youtube.com/watch?v=4XpnKHJAok8 [1] https://www.youtube.com/watch?v=-F-3E8pyjFo