This result holds on average over all languages and for five out of thirteen of the individual languages and shows that the advantage of linear-time parsing complexity (for the stack-based parsers) can be outweighed by the disadvantage of a more complex classification problem in pseudo-projective parsing.
the larger constant associated with a larger cohort of SVM classifiers for the pseudo-projective parser can be more important than the better asymptotic complexity of the linear-time algorithm in the range of sentence lengths typically found in natural language.