They provide a more objective basis for annotation, and they can presumably be aggregated to provide an empirically grounded picture of user-level behavior (or others' reactions to such behavior).
for positive instances of condescension, we further limited our attention to COMMENT/REPLY pairs in which the REPLY contains a direct quotation from the COMMENT, using fuzzy match based on Levenshtein distance (Navarro, 2001), as illustrated in Figure 1.