The
reason for this is there are many more hand combinations in pot limit
Omaha (you get 4 hole cards instead of 2), and as a result many
more hands are out there than there would be in hold’em, making the
likelyhood of bigger full houses being out there extremely high.

An example:

You are playing against a solid opponent and
you flop the nuts with nine seven on a 9c9s7h board. Your opponent
checks, you bet and your opponent calls. The turn is the Kh, and again
you bet and are called. The river comes out a the 10h and your opponent
bets pot into you – what should you do?

In hold’em,
you’re praying that your opponent made their straight, and you’re
getting a big payday (or even had pocket 7’s for you to have the better
boat).  But in Omaha, in this situation, Against a solid
opponent your hand is basically never good here. Although it is
probably worth calling against a complete fish, most of the time here
your hand is clearly beaten. There are
many hand combinations that you lose to here. Your opponent may have
called on the flop with a pair of kings to see if you would continue
and turned a monster, although most likely they probably have a hand
with a nine in it that also contains a king or a ten or pair of tens,
and have turned or rivered a bigger full house.

The honest truth is a lot of players come from a hold’em
background, and will have a really hard time getting away from any boat
(Which is why you pray your opponent had pocket 77’s in the scenario
above).  A very seasoned Omaha player will be able to see the that he
is likely beaten and will be able to fold.  A more unseasoned Omaha
player, will know the THEORY that he is likely beaten, but will talk
himself out of folding because folding a full house is not accepted
strategy in Hold’em.

Remember
that Omaha is a game where most of the time the hands are out there,
and the spots you call and bluff in have to be adjusted accordingly.
Although it really stings to fold hands like this – especially if your
background is in hold’em – in Omaha you have to be able to make lay
downs like this on a regular basis to stay afloat, no matter how much
it hurts.