The reason is, in the typical contentious low-level development human interaction, one developer is an idiot with insane scrublord opinions, while the other isn't. So the first developer has an inflated ego, and the second doesn't, and people standing on the side who don't have a clue which is which. In this case, we have one who thinks it's reasonable for the debug flag to bring down the system, and the other is a sane reasonable person who's not going to tolerate this crash-the-planet type behavior any more.