I don't really know about how boring a really realistic game could be, as there already are several games that tries too hard to be realistic they are rather not very realistic at all.
But there are other realistic games which are popular, take for example: Americas Army, Now that game is obviously a ground game, without vehicles and such (It's been a long time since I played it).
Anyway, it is popular and realistic to a certain degree, probably just what you guys are talking about, but when it comes to a complicated game with vehicles it is not easily done to make it look both realistic in air and ground at the same time.
Take Battlefield 2 for example, that game is a bunch of bs. Although it is a game with alot of fun, I've spent hours on great fun.
But what I think that is the most important part in all games, specially when it comes to the line between realism and gaming experience, is the team you play with. It is all about teamwork for some games, and other games not.
Anyway, If you have a good group of gamers you play with and you all are on the same page, and have the same ideas the game will be fun wether it is an extreemly realistic or not.
Is it just my opinion or what?