I agree with all above about how this can be due to the fact that most viewers are female and therefore project themselves more, and also about the weakness of heroines being irritating. I would also add that again, since the majority of the viewership is female, drama writers (in romantic dramas, and rom-coms in particuliar) tend to try to make the female lead more "relatable" -- which unfortunately often menas they have a very exaggerated negative trait, such as being petty, or grumpy, or dumb, or messy etc... Often it's with the female lead you "spend time with", you see her living daily. However, in many cases the male lead is written as more of an ideal (he has flaws, but generally they're things like "aloofness", which again puts the hero even higher above the heroine, who is often loud etc). It's often "the prince" that arrives into the heroine's life, and rarely "the princess" into the hero's life. Of course this is only for some dramas and is not general at all, but I find it quite common -- Playful Kiss, Scholar Who Walks the Night, Boss & Me, Boys Over Flowers, The Master's Sun, You Who Came from the Stars... It's not necessarily a bed thing, it's just the way many dramas are structured.
