The game usually does give correct advice, however. Bob Dancer's article A Look at DreamCard -- Part I of II says that when two more or cards are tied, the game will sometimes tease the player with a card that might lead the player to play incorrectly. Take the following two screenshots of VideoPoker.com as examples. In the one on the left, the game correctly gave me a card to complete the straight. However, any six or jack would do. I don't think it was random that it gave me a heart, tempting me to go for the straight flush. In the hand on the right, the game was correct to complete the flush with any spade. However, it gave me the jack of spades, as a temptation to go for the royal.
Isn't it possible that, instead of something psychologically nefarious, as is suggested, it is simply that the dream card algorithm is giving the player the best possible card for a multitude of holds? Not as an enticement to play incorrectly, but it's just the best possible card to give the player even if they make a decision that is technically incorrect?
In the first example, the deal is Th 9h 8s 7h DC. The DC given is Jh. That is the best card to give the player whether he holds the straight flush draw OR the straight. The same applies to the second example where the deal was Qs 2s Ks 8s DC. The DC given was the Js, which makes both possible holds (flush or three to a royal) the best they can be. Note that it wasn't a 10s or As, but the Js which is the most valuable royal card to give a KQ.
ETA: If they wanted to entice the player to make an incorrect hold to the casino's advantage, they'd give a 6h (still completes the best hand (straight) but gives a 6 instead of a possibly-paired J) in the first example and a 10s in the second. (Drawing to KQTs is less valuable than drawing to KQJs, but the player is still given a card that completes the flush).