When you celebrate layoffs at a studio because the game that you don't like didn't do that well, you're crossing a line
No you don't? If you do a bad job and get fired for it, it's not crossing the line just consequences of doing bad job. Your circumstances aren't really relevant here, just own your mistakes and move on.
There's everything the other comments said but there is also an important distinction in "celebrating". I would argue that while layoffs as an event are a potentially logical outcome of a bad game, it is the act of celebrating and/or calling for those layoffs that is crossing the line.