It depends on the person. Different people have different motivations for wanting an article deleted:

- Purism with respect to Wikipedia policies (I would place this example in this category)

- Ideological commitment to notions about what an encyclopedia "should" be

- Personal vendettas

- ...and so on

Its simple really: wikipedia shouldn't be the dumping ground for any and all information--that's what the internet is for.

In this specific case, the only notable thing about this guy is that he invented clojure. Thus he should have a mention or a footnote on the wikipedia page for clojure. He hasn't done enough to himself be notable.