For now they do. But notice the large number of Ubuntu-exclusive programs that they use. And that's not because of technical merits (otherwise they would have been adopted by others). So Ubuntu is just making itself way more distant from what is the norm in the other distributions. It's becoming an outlier, it's not representative of GNU/Linux as a whole. That's what I don't like - it is still true that Ubuntu is the most popular distribution, and thus the first distribution new users are likely to look at, and if they see an outlier instead of something close to the average, they won't know what GNU/Linux actually is.