In WotLK you had 8 reps at start: Argent Crusade, Knights of the Ebon Blade, Kirin Tor, Kalu'ak, The Wyrmrest Accord, The Sons of Hodir, The Oracles, Frenzyheart tribe and a generic Horde / Alliance smash faction.
3 of those rewarded pretty sweet mounts.
Others rewarded naxx10 equivalent gear.
For some of them you had to run a relatively low number of dungeons to get to exalted. For others you had to run dailies for a week or two. None were too grindy.
Enter Legion. 6 reps, none of which reward anything noteworthy, since heroic warforged / titanforged / whateverforged gear outperforms them by far and mounts are nowhere to be found.
And the only way to get rep is to crush some nuts for 75 rep