How about this?
In addition to being restricted to Pure-Bloods, Durmstrang has another distinction: its culture is absolutely Quidditch-mad. (Victor Krum is merely the most spectacular of its sports programme's many successes.) To the canon!Malfoys, this would only add to its attractions, but the more intelligent MoR!Malfoys realise that Quidditch is an asinine game. While association with the popular sport could be beneficial, it simply is not worth the drain on mind and spirit.
its culture is absolutely Quidditch-mad.
How does this distinguish it from Hogwarts, again?
It seems to me that the best explanation is pretty simple - Hogwarts is just the best, by a large margin, with the possible exception of Defense against (using) the Dark Arts, where Hogwarts is usually handicapped by its horrible professors. Since Draco already learns combat spells from tutors, this seems like a pretty small price to pay. Also, given that the Malfoys are playing for power in Magical Britain it makes sense to have been educated there, both not to ...
Update: This post has also been superseded - new comments belong in the latest thread.
The second thread has now also exceeded 500 comments, so after 42 chapters of MoR it's time for a new thread.
From the first thread: