Why is disagreement within the legislative branch beneficial, while in the executive branch it is detrimental

Disagreement within the legislative branch can usually lead to good things. Then the congress is arguing about something, two sides want their side to win and they represent two sides of the population. When they manage to find a solution or common ground on an issue, that means that it's usually a compromise so the thing in question moves forward a bit in such a way that it suits both sides a bit.

Disagreement in the executive branch however is not beneficial because it can cause delays in administering laws or signing them into the official lawbook, or it can cause for people who did something bad to answer for it at a later time which gives them time to escape, or anything similar. Nothing good can come out of disagreement within the executive branch.