No, I don't agree at all. In the past two years I've watched some fluffy silliness, but also some really beautiful dramas with meaningful themes, well-written and well acted.
Pinocchio. There was a love story, poignant and sweet, but it wasn't a rom-com, and there was a very serious issue underlying the whole thing: the responsibility of the press in ruining people's lives.
Romantic Doctor Kim. Where by "romantic" they mean "idealistic", since the good doctor has no romance in the series. There is a romance between two other doctors, but the main theme is moral responsibility of a doctor, career versus care for fellow humans and so on.
Solomon's Perjury. A youth drama, with no romance at all. How does a whole class react to the suicide of their classmate. Who is responsible? Is there even a responsible or is everyone responsible, either for doing something or for not doing and just watching?
Jackpot. Not consistently good, but this series (where the romance is underplayed and then completely ditched, thankfully) focuses on the implications of ruling, the compromises that power dictates and how it changes someone's character, the choices one should make in order to live life as he wants it, and how far one should sacrifice human beings to bring on an utopian better governance.
Another Oh Hye Young. There is a strong love story there, but it's also two deeply scarred people learning to open up and heal their wounds.
W. Apart from the love story (which all but disappeared in the second half), this was a roller-coaster of unexpected twists and turns, a tale of two worlds, the "real" world and the world inside a comic book, and how the comic book character gains conscience of himself and becomes alive. What makes a human really human, what does it take to become human? It was extremely interesting and, although most of us thought that the ending episodes were not satisfying or well-rounded up, still I think that none of us would regret watching it.
Tomorrow with you. Interesting take on time travel. Yes, it has a love story, a very beautiful one, but it's not a comedy. The eternal question of how can you influence the present if you know the future, and should you do so, is intelligently explored.
Goblin. A love story but also a tale of redemption and forgiveness. Where pure, innocent love can help bring redemption, can help someone find a meaning to life, the will to go on living. Brilliantly made, with top-notch production values and especially lots of atmosphere, with a great OST. The main girl's smile was something that stayed with me.
Chief Kim. A quality comedy with no romance, and a strong social message, about a man's transformation from crook to hero.
My Wife Is Having an Affair This Week. Intelligent and sensitive portrayal of the various stages a person goes through when discovering his world collapse. No makjang here, very human and realistic. Brilliant acting by Lee Sun-kyun. One interesting thing here is that the betrayed husband turns to an online forum for support and advice, so a strong sub-plot is the netizens' reactions and their influence in his decisions.
Chicago Typewriter. It has a love story, and a few comical moments, but most of it is a gripping tale about past life, about the heroic self-sacrifice of freedom fighters, about writer's block, about the role of the media, internet and the fans who can make or destroy a celebrity, about reincarnation and fate, about friendship... Love is only one of the many strong themes here. I started this drama doubtfully, but it became more and more gripping. It also felt as a detective story.
Memory. An incredible series with an incredible actor giving his all.
I would also mention It's Okay, that's Love, with its brilliant take on mental illness, touching on all kinds of love, not just romantic love, but affection and acceptance of fellow-human beings, flawed or not. And of course the top of the cream, Misaeng: Incomplete Life. But both are from 2014, so you might say we are not talking of older dramas.
As for longer, weekend series, I liked Five Children a lot.
The problem with weekend dramas and the reason for which I don't usually prefer them is that they cater to families with many very traditional-minded viewers, so they have to be very careful in presenting anything that differs from traditional values. But this one, about remarriage of a widower and a divorcee with kids and they problems they face both before and after it was very intelligently made, well acted by almost everyone and the comedy was not over the top. I really enjoyed that one.
Much more than "Father is Strange", currently airing, where the makjang factor is strong.
House of Bluebird was also good until a little after halfpoint - then they changed the writers and it seemed that the second writer didn't even take the trouble to attentively watch the preceding episodes. And the ending really really sucked. Ugh. Too bad, because the revenge and forgiveness story was well carried out .