I think it's partially due to some people being really demanding and honestly rude about the game not being released. However, Laly also set an expectation of herself and it's normal to feel down when it isn't met.
I really hope she will realise that her health is WAY more important than releasing her game.
If people have to wait so be it. No one will die from the game not releasing today.
I'd rather have a later release that'll end up with the creator being happy with what they made, than a rushed game and a creator on hiatus.