This is like asking why ethnically African people have a greater right to Africa than non-African people. Sounds dumb doesn't it?
Ideally, this would be about all of us humans being responsible custodians of the entire earth during our short passage here.
In the mean time, you're free to celebrate this baby step towards humanity in France.
The sooner there is no longer even a concept of 'European' or 'French', the sooner humanity can move beyond racist policies such as in the related link.
France's colonies were, unlike Britian treated as part of france. That meant all of these areas in blue: https://en.wikipedia.org/wiki/French_colonial_empire#/media/... are french, with the entire population being french citizens.
So this means that someone who is algerian could have french parents, but not be eligible for french citizenship. However if I as an EU citizen wanted to live in france, there is nothing stopping me.
In the same way that up to the 70s an english "colonial" had the right to a british passport. Until it was decided that it wasn't acceptable to have too many "colonials" about the place.
Also, anyone with (at least one) French parent, is eligible to citizenship.