The Relationship Subplot

As I said in my opening post, I’m new to the writing game, and one of the things I’m struggling a bit with is the subject of protagonist relationships.  I’ll find in otherwise good books, books with major page-turning plots, books by very successful authors, oftentimes a secondary plot that deals with the protagonist’s personal relationships – e.g., the rocky marriage, the wife who complains the hero’s working too much, the ex-husband who doesn’t pay alimony, the pain-in-the-ass teenage daughter, etc. In other words, a secondary plot that isn’t really germane to the main storyline, but which, I guess, adds a human dimension to the protagonist. One writer who I admire/like very much seems to devote about every other chapter to the relationship between the hero and his girlfriend, and I actually skip those chapters because while I like his writing, I usually find the relationship subplot a tad boring. But I’m curious about how others feel about this sort of thing – do you enjoy the relationship subplot or not?   The reason I’m asking is the protagonist in my books is Joe DeMarco, divorced, not yet lucky in love, and I’m pondering his future.