This "only play the nuts..." business in O8

[AKQJ10]

I have to admit that i'm a bit confused about the oft-repeated advice "only play the nuts or a draw to the nuts" in Omaha 8. A hand i just played at Pacific's .05-.10 table illustrates the kind of thing that drives me crazy. (I'm going from memory because Pac's silly animated history isn't working.)

My first hand in, posting the big blind in the cutoff, I get dealt JJ74 with the 74 suited in diamonds. 7 or so limp in. I flop the nut high, 653 rainbow, with the 3d, although that puts a low on the board and may well be one of the "sucker straights" discussed the other day. I bet it pretty aggressively anyway, putting in the second raise, because I figure that I can possibly drive out some of those other potential hands to beat me, but there are still 5 or 6 left in the pot. The turn is the 6d, so now bigger hands are possible but i'm also drawing at a straight flush. I back off but still end up calling 3 bets IIRC. Then i river a jack, which means i've now got the biggest possible full house, so i reraise on the river and we end up capping it, still 4 or 5 people left in the now-immense pot.

You can probably guess how this story ends; someone shows down the other sixes to make the only hand that can beat me. I wasted 10 BB or so chasing a nut hand that turned into a totally different 2nd-best hand. I can't imagine that i misplayed this, other than possibly putting in that last raise (I usually forget to consider quads when quizzing myself on "What is the nut hand now?"). I know the chances that both sixes are in the same hand aren't infinitesimal, but my play should be +EV shouldn't it?

I'm particularly frustrated because of a bad 11-hour O8 session at Foxwoods yesterday, but that's a story for a different post (if i get around to it)....