We want realism for things that are real in our every-day reality. Such as arrows, swords, horses, item weight, food, etc, etc.. It makes sense to have realism, so that we can relate to the world that we are playing in. It gives it a stronger feeling that it could actually exist somewhere in the universe.
We also enjoy the imaginative side of the game, such as magic, dragons, and lore. This is the main reason why we play these games. It's fun to immerse yourself in a foreign and exciting world where you control the fate of your character and other non-player characters. Does this mean that we want to add realism to magic? How could you? Magic, as portrayed in the game, simply isn't real.
We do, however, want to bring a balance to these things. We don't want magic users to be able to run around casting apocalypse-level spells at whim. And we want it to at least bring some rationality and realism behind these mechanics. For instance, opening locks. If I can open a lock with a metal hook and screwdriver, then there is no reason not to include an open lock spell for magic users. It doesn't break the game, it doesn't make magic unfair, and it certainly doesn't force you to choose the lockpicking skill if you want to open a lock in the game. As if every character is now some kind of trained thief, regardless of how they want to role-play or regular-play (is that a correct term?

on a related note, I want lock bashing for the warrior-brute players. It's only fair.