The main problem with this move is that it doesn't develop a piece and lack of development can be fatal in many of the sharp lines in this opening. In addition to being a non-developing move, it is a non-developing move that blocks a threat that doesn't need to be blocked. The reason 3...h6 gets played is that Black is afraid of 3...Nf6 4.Ng5, however after the mainline moves 4...d5 5.exd5 Na5!?, Black's position is considered perfectly playable.
Black has sacrificed a pawn, but he has very active piece play as compensation.
Of course, sacrificing a pawn so early in the game as Black is not to everyone's taste. (It's not to mine!) Hence, Black's other main move 3...Bc5. Note that 4.Ng5?? loses to 4...Qxg5. If White delays the knight sortie with 4.0-0 Nf6 5.Ng5, Black simply replies 5...0-0.
Now Black is ahead in development. So what should White do if Black wastes a move with 3...h6? The best way to take advantage of a lead in development is to open the position up and attack. 4.d4 exd4 5.0-0 Bc5 6.c3!? looks like fun to me.
On 3rd Board in the Buffalo Grove match, White played the perfectly reasonable 4.c3 d6 5.d4 and Black played 5...Be7. White replied with the disappointing 6.d5?!
This move is disappointing for both tactical and strategic reasons. The tactical reason is that White could have won the f7 pawn with either 6.Qb3 or 6.dxe5 dxe5 7.Qb3. The strategic problem with the move is that by closing the center White will have a much harder time exploiting his lead in development.
The other question to ask is "What's the rush?" Even if closing the center is desirable, there is no need to do it now because Black sure isn't going to want to prevent it by exchanging pawns. For example, after 6.0-0 exd4 7.cxd4, White has an absolutely lovely position with dominant central pawns and c3 available for his knight.
There was no reason for White to release the tension so soon. By maintaining his lead in development, he could have kept Black guessing about his intentions.