Gaining rep via Tabards came into being during Wrath, and was continued in Cata. I personally found using the Tabards to gain reputation an improvement over the model in TBC (reputation being locked into a few turn-in quests and specific to certain instances) or the Classic model (almost purely a turn-in system and onerous to the extreme). That being said, gaining reputation via the Tabards tended to remove the emphasis of a faction almost completely - to this day few people seem to know what factions such as the Ramkahen or the Wyrmrest Accord were even about because they had little to no story to them. Reputations with daily chains tend to be far more fleshed out, and can even foster a sense of involvement if their stories prove to be compelling enough.
This is not to say that MoP's system doesn't have faults, as it certainly does. But I've found the MoP factions do seem to matter a lot more, at least to me, and the epic Exalted quest/events of the Golden Lotus, Klaxxi, and Shado-Pan factions were awesome to behold.