I understand the sentiment, but I think this is partly an illusion. You are "reaching your hands in" as a GM every time you make a judgement concerning what is "realistic". Your model of reality is, assuming that you are like every other human on the planet, both in some respects wrong and in some respects different from those of everyone else. The reason you feel more comfortable making rulings based upon it is that you are naturally disposed to consider it to be "only common sense". Your model represents deeply held beliefs about reality and,
as recent research has clearly shown, this makes you extremely reluctant to change it. The truth is, though, that it's no more reliable than anyone else's - and those are not very reliable at all...
At risk of repeating myself, this is a trap - and one that is very easy to fall into. Human beings are fundamentally incapable of simulating all aspects of reality because the models that they believe are true about reality are all wrong. They are a fair approximation for many situations that come up in everyday life, for sure, but outside of that they can be hopeless. In the real world this does not matter, because we have one simulation that is flawless - reality itself! Any misconceptions we have will be swiftly pointed out as soon as we encounter them
in person. In a game, though - and one that seldom restricts itself to "everyday life" - such a model is not available. Which is why we so often see blazing arguments between gamers adamantly arguing that such-and-such a system should work in such-and-such a way because that is "realistic"...
The answer is simple. Forget "realism" when playing the game - just use the rules for how the game world works. Consider the real world when designing the rules, fine - there is a lot about the real world that is elegant and neat, so it makes a good source of inspiration. But if you build a system in an attempt to model reality perfectly you are on a fool's errand and doomed to disfunction. And if you try to wrangle the system on the fly to be "realistic" you have the same problems, but now you add those of time pressure, adversarial considerations and lack of player foreknowledge.
If I wasn't willing to change, the style of game I enjoy now would be exactly like D&D 3.5, and I'd play in a manner consistent with the person I was at the time I first learned how to play tabletop rpgs.
I will openly admit that I do not know everything about reality. However, I'm willing to argue that taking an arrow to the face is generally severely crippling or fatal as opposed to being a minor inconvenience. I don't ask for perfect reality, and I hate to even use the word 'reality' when speaking of rpgs, but I expect a certain general ballpark of consistency when compared to what I can see around me. In many cases, that 'ballpark' is very large; a lot of things can fit into it, and I'm even fine with making sacrifices in the name of playability and fun. That being said, when I start to feel as though I'm fighting against a game which should be fun rather than working with it, that -for me- is a problem.
While, yes, I do make judgements, I do so as an out-of-game entity as much as possible. When it comes to in-game, I prefer to meddle as little as possible, and the choices I make for NPCs is (as much as possible) based upon what they can see, hear, know; etc.
As for a fool's errand being trying to make a plausible game. I disagree. While even the games I prefer do have problems and areas which aren't at all realistic to me (an easy example is rapid fire rules; I've fired weapons on burst fire before, and it certainly isn't more accurate,) it is possible to create a game which is close enough and still fun. I'd go so far as to say many of the games I have in mind are far less dysfunctional than I view D&D to be given similar in-game situations.
Can I know how a magic fireball would realistically react to something? Obviously, no, I cannot because wizards and magic do not exist. However, that does not mean I cannot still expect some level of plausibility. I expect that magic fire should burn things; once it comes into play, it should behave like fire. I have no way of knowing exactly what elves might do given a situation, but (in most settings) it seems 'realistic' that they need to eat; that they have hearts and lungs and eyes in a manner similar to humans.
For me, having that plausible baseline helps me; I don't find that it gets in the way. Even now, I'm running a super hero game, and the PCs are capable of doing things which are miles beyond anything that could even conceivably be considered realistic. I'm completely fine with that; it's fine, and I'm highly enjoying GMing the game. However, in spite of all of the unrealistic elements, there is still a shared baseline between myself and the players. I don't believe we've ever run into an issue in which there was a disagreement over whether the guy who can turn his skin into metal would be more susceptible to something like a heat metal spell compared to a normal human being; I don't believe we've ever had an argument over whether or not a hero might still drown after being knocked unconscious and thrown into a river. I don't believe there's ever been a situation in which I said "no, that doesn't work because the game rules say that someone of your level can only do X." Instead, I've more often said "I'll allow you to try, but understand that this is the situation you are up against..."
Maybe I just tend to play/run rpgs in a strange manner. Every time a similar topic comes up, I don't feel that I can relate to what seem to be the usual viewpoints. All I can really tell you is that -for me- the added realism (even if it's not perfect) helps my narrative; it doesn't get in the way of it. I don't in any way find that reality hinders my fantasy; instead, I find that reality does a really good job of complimenting my fantasy and making it feel both more real and more magical.
