Each year , dramaland takes on a topic !!

I noticed it too.  Then there was a fantasy genre trend after you who came from the stars with blade man and surplus princess.  I think they're just trying to cash in on the hits but usually they end up not being as popular.  This new batch of dramas is not too bad from what I've seen though which I'm happy about.  Although I didn't watch too many kdramas in 2013 and 2014, what I did see didn't really impress me.  Atm I'm really liking Healer and Heart to Heart so 2015 is looking good.

I think we also had a lot of time travel/go back to old life and also law dramas this year:

Hit the top, Dr. Heo, Chicago Tipewriter (kind of), Go back couple, Manhole (didnt watch the last two, but I think they are about going back to youth and re-do life). 

Defendant, Witchs court, Suspicious partner, While you where sleeping (law)

I can't say they copy each other, because probably they have to submit all the proposals for dramas really early in the year, but how it really could be so similar? Maybe there are some popular topics in SK, maybe novels or something... dramas could be just following the trends, just like when Twilight, Harry Potter and 50 Shades of Gray were released, a lot of things releated to this topic became popular in my country (just a guess though, I don't know for sure...)