I think the basic problem is that your hand isn't that strong against 5 players drawing. If you hadn't hit your full house on the river you couldn't be sure You had the best hand. Another issue is that flushdrawers won't pay you when they don't hit on the river, it will be too late to get paid.
That's why you have to get paid while you're ahead and someone is willing to pay you.
Let me ask a question: If a random card other than the jack had hit on the river, would you still have claimed your price for trip A's ? What if a 7 had hit ? A club ? Most of the times the J won't come around on the river...