I think the purpose of realism depends heavily in what the game is trying to achieve, either a Puzzle or trying to create a Story. One of the most important part of an RPG is the Narrative, also known as the Story Telling.
The Narrative is a Good thing. Liking RPGs for the Narrative or Storytelling should not diminish anyone's "gamer cred". In Origins of the Human Mind by Professor Hinshaw I learned the important of the Human narrative and how it Humanizes characters, people, and others. The "narrative" is not only a great way to learn empathy, an appreciation of humanity, and the great things people are capable of, but it helps people resolve personal struggles.
As much as I am a geek for games, I learned in a Psychology and Cognitive Science lecture enjoying a Good Story has a lot of validation. I recommend the Hinshaws lecture.
Realism is for the Challenge. The more you scale a game towards realism, the more complex and difficult things become. Realism is a GM tool in creating validating/useful problem solving scenarios.
Realism is very important in maximizing the authentic feel and difficulty of the real world challenge in a safe and learning focused simulations.
I think, Realism is the spice we put in fun to build up our tolerance for problems and life's awful complexity and baggage.
Realism is not a merit of Good RPGame. I used to be carried away by realism, of course its because of my OCD quirk, but tunnel vision is a common problem in any mode of thinking. Games are enjoyed only by people who can relate to it, and levels of realism may not be appropriate for the Players or even a GM. Appreciating Realism means also appreciating the complexity of how reality really works and that assembling a system to simulate it may not be the best use of time and resources of the GM.
Realism is only a merit in a simulation, and a simulations can, but rarely, are an RPGame.
In Real vs. Cinematic - Steve Jackson Games Forums i think the OP needs to reframe the question. I think it should be a more "objective" analysis of the wants of his players than his own wants. I think a survey to look at the strongest common interests and mutual expectations can help resolve or answer if a particular system is best. Nothing like communication in maximizing utility from an endeavor among allied parties.
I've tried researching more about Simulations for a Business Plan designed to attract more people to adventure tourism in the Philippines and one of the things I learned is how freaking complicated it is.