Every MMO is a time sink to some extent. Daily quests, repeat boss and dungeon runs for specific loot drops, crafting, multiple characters, etc, etc. I've played a bunch of MMOs, and come to expect it. Even so, I think Blade and Soul is a pretty extreme example when it comes to how much time the game expects the player to spend.
as I mentioned before, the story is all very generic. Doing it once is mildly amusing. Doing it again gets old fast.
The most obvious time sink is crafting. The way you get raw materials is to put in an order with a gathering guild. The lowest level orders take 30 minutes to fill, and the time goes up from there. Then you turn over those materials and some other rare items to a crafting guild, who spend more hours making an item for you. The good news is that those countdowns continue while you're offline, but the bad news is that you have to log in to set up new orders as the old ones are completed. Lots of MMOs use this approach, but very few have this kind of length. (For comparison, Star Wars: The Old Republic gathering missions mostly take 3 minutes at low levels.)
Then there's that "other rare items" that I mentioned. All but the most basic crafting requires special items that come from random drops in boss fights and daily quests. Many of these aren't tradeable, so the only way to get them is to go do the quests...another time sink. Daily quests aren't anything new in the MMO world, but again, Blade and Soul stands out for the sheer amount that it expects you to do in order to progress.
Even daily awards require more time than I usually see in these kind of games. Blade and Soul has a "Daily Dash" where you spin a wheel to get a number, then move a token that number of spaces along a game board, and get whatever item you land on. You get multiple spins, but you can only use one per hour. So in order to even get the full daily log-in reward, you have to play the game for multiple hours.
Finally, there's item upgrades - probably my least favorite example of how Blade and Soul eats up your time. At several points, the only way to continue to upgrade your weapon (at least, as far as I can tell) is to defeat a world boss, take reward tokens that he drops, and spend those tokens on a "wheel spin" where an NPC gives you a random item. You'll eventually get a weapon box, which you then have to open and hope to get something usable by your class. It's not tradeable, so you can't buy one or sell your extras. It can take dozens of attempts to get what you need, which means a ton of boss fights, which means sitting around with a lot of other people looking at the ground until the boss spawns and everyone jumps in hoping to get a few hits in so they get a reward. It's a terrible player experience, combining the worst of boredom (waiting on the boss spawn) and frustration (getting useless crap from the random wheel spins).
Blade and Soul has some good aspects, certainly. There's some really good art and animation, and some interesting combat moves (even if it's not really my favorite style). It's fun to play as a duo, at least as long as you stay away from the 6-player dungeons. But the sheer amount of time needed to progress means I'm unlikely to stick with it after I've made it through once.