From what I have heard and deduced from the Blue posts.. The decision was based on the fact that, back in the day Goblins stopped at the same. Over time, I believe those factions were fixed and the Bloodsail was not.

From what I gather, this achievement was designed to finally put the nail in the coffin of "reputations that do nothing". Blizzard made em, didn't cap em.. and wants to reward the people insane enough to do them.

Bloodsail is possible to get to exalted through tedious grinding of a mob that respawns and gives 5 rep per kill in Badlands. It's stupid and not worth it. It's the ONLY reputation I wont grind.

So yea, its more of a "they just didn't" answer. And rather than fix it and screw EVERYONE from getting it prior to 3.1 (Therefore slaughtering Goblin reps again), they just left it the way it was.

what's the rep required for the hat? Just Honored or is it friendly?

@Dizaster

Interesting, thanks for the info. After reading about the mob you mentioned:

http://www.wowhead.com/?npc=9179

There should be an even more insane rep reward for exalted with Bloodsail. That, is utterly nuts.

The quest for the Hat gives 500 rep and is available at friendly.

Jazzrik in the Badlands give rep only through revered, you will stop at 20999 and not get rep the rep to put you over to exalted. The only way to get to exalted is to save the hat quest until after you're done with the 4101 Jazzrik kills needed to get within 500 rep before exalted.