I write romance. Still unpubbed, but the way I view the introspective portions of the prose is that I write it this way and someone else can write it their way. Because I started writing with fantasy, I don't like the uber long passages of introspection either. I get bored and lose focus. In my work, I have a lot of introspective sections, but they're only a few paragraphs long. A page or two, at most. They get longer toward the end, as resolution demands. Because I prefer action and dialogue, and I find it's just as easy to intersperse a character's motivations and feelings and growth through those things as it is to use meandering monologues. No one has told me that I don't have my characters do enough introspection and I don't spend less time on the feelings portions of the books than my fave romance authors, so I feel like I'm not doing anything wrong.
My conclusion is that there isn't a definitive answer. Each novel is different. Each writer's voice is different. As long as you are showing your characters' motivations, feelings, and growth, as long as the reader feels connected and can understand why they feel the way they feel, you're probably fine.
