My neighbor receives welfare and SSI and has been very open (for what reason, I don't know--I never asked!) about her income. She lives on less than $12K per year, and raises two children on that money (she also uses disposable diapers and used formula for both of them so those are huge expenses, too). She never goes anywhere. She doesn't even own a car (or know how to drive). I can't imagine how she'd ever have the money to go on vacation, unless a family member paid for it all. Her grandmother is considering taking the whole family to WDW in a year or so. There really isn't anything she can do about the gift of a vacation vs. a cash gift or money to pay the rent, other than turn it down. In fact, her relatives (mother and sister) are already paying some of her bills because she literally doesn't have anything leftover after paying rent and buying necessities (TP, the aforementioned diapers, etc.). IMO, she'd be stupid to turn down a gift of a vacation just because she's on welfare, because her kids literally never do anything. It's almost pathetic.
This is my opinion about anyone receiving any type of assistance, whether or not I approve of that program or that particular person receiving the money. What's done is done (income redistribution), and what's offered is offered (gifts from others). But I can tell you that there is NO WAY POSSIBLE she could afford a vacation of any kind on the income she receives. Maybe the OP was referring only to those who are scamming the system??