The main problem with this analysis - I think - is that each language rank as 1, regardless of actual speaker size and history. There is a reason why some languages are much larger than others (mostly historical and political), and these larger languages (like English) has thus evolved towards a more simplified version of its former self.

English is thus - for all intends and purposes - not weird.

A more interesting approach would be to take larger languages, like English, Mandarin, Spanish, etc. and value their features higher than languages spoken by tribes or very few people, and thus you could determine a more accurate 'weirdness' index out of that.