Humans probably counted more on/appreciated Elrond because
1) The elves of Rivendell (and Grey Havens) had been allies with men, f.g. in the wars against Angband.
2) Rivendell was probably a more welcoming place than Lothlórien; in Rivendell everybody was welcomed and cared for whereas in Lothlórien you could be pierced by an arrow if you couldn't explain yourself and very few Men were let to enter the kingdom.
3) Elrond descended from Men as well from the Elves, so maybe the Men (subconsciously) felt some kind of connection to him.
