Why are gargoyles evil?

[LuisCarlos17f]

If you want they aren't evil, only living constructs created to be the hidden sentinels of castles and strongholds.

Usually the ugly monsters are evil.

 

[Bootlebat]

I don't think of gargoyles as being evil for the sake of it, rather they're ambush predators who have adapted to an urban environment.

According to the 3e Monster Manual they don't even have to eat to live but just do it because they like hurting people. THAT is evil.