The author (Ubersmekel of the eponymous Uberpython Pythonblog) dislikes that errors are passed as return values from functions, rather than percolated and caught/handled as exceptions. He or she feels that it is verbose and encourages the missing of maybe-important errors. The author also feels that panic and recover are ill-applied, at least in the standard library. These perceived shortcomings are sufficient not to leave their current language (likely Python, given the blog title).
And how does this add anything to the discussion that hasn't been said 9000 times?
This article is also from 2012
And is the 3rd time submitted to HN by the same user.