So there’s nothing wrong with interpreting Buddhism from a particular cultural standpoint. But to assume that your interpretation, because it’s not bogged down by (Asian) cultural baggage, is somehow better than what’s come before is the height of arrogance (and, frankly, insulting).
All Buddhists are modern Buddhists if for no other reason than the fact that we all live in the modern world and, therefore, need to deal with a similar set of modern crises. (Do you really think Asian Buddhists are all still living in Ming Dynasty China?)
All Buddhists are in the process of reinterpreting their traditions, making deliberate and creative changes to the doctrines and practices in order to help them make sense of these troubled times.
The problem is when you make the claim that your Buddhism is more “authentic” than someone else’s Buddhism (because, ahem, that’s the very definition of fundamentalism), and then take that added step of claiming that your Buddhism is more “authentic” precisely because it is not the Buddhism of some “other” Buddhist.
When you make that claim, you are not only defining yourself, you are defining the “other” and, like I said at the start, no one likes that. So knock it off.