Why does the greek gift sacrifice not work in this position

I wonder why the greek gift sacrifice doesn't work in this position after 7...Nbc6 and stockfish calls Bxh7+ a blunder. I know it eventually worked because the opponent blundered, and then I blundered and drew the game. But I can't figure out why Bxh7+ is deemed a blunder. I controlled the g5 square, and my opponent didn't have a move to easily defend h7.

it doesn't work because after you played bxh7, all black had to do was play kh6 and it was safe as it would then probably followed by ng6 if you brought the queen out to attack. And after those 2 moves by black you have nothing

Black can indeed play Kh6 and Ng6 to try to stop my attack, but for example in this typical line in the French Winawer variation, Black can also play Kh6 and Ng6, but the greek gift sacrifice works though

Black CANNOT play KH6 in that set up because white plays Queen g4 and it's mate in 4. The reason why Greek sacrifice works in the second graphic you've posted is because you have a bishop on c1 protecting the knight/square and pawn on e5