Shen Sui can certainly understand why new Life Card Masters construct decks leaning towards the Underworld style.
Normally, if your luck is bad when drawing Soul Cards and you get a Soul Card Follower that hasn't grown in strength yet, you basically won't have any strong followers unless you spend a lot of money to buy some.
Without powerful followers, you can't rely on the mainstream ways to win duels. You have to look for means in unconventional areas, and naturally, the deck's construction becomes more Underworld-like.
Although Life Cards aren't too expensive domestically in Huaxia, an 11 or 12-star Follower Card officially sells for over ten thousand, but you basically can't find strong followers in the official Life Card Store. People use offline channels to sell cards at higher prices.
With online shopping being so advanced now, it's the domestic environment that has kept the Life Card sales system more focused on offline channels.