Maybe because new fans for LOSH really aren't there for it. It is a "dated" concept because most kids of today are NOT into groups or clubs. It is a world of Individuals. Hanging out together as a "group" isn't what kids do today. The only large groups of kids you will find  is via internet connect these days via chat rooms or group gaming and not in person.


Plus, the old guard fans want the "traditional/classic" LOSH they grew up with, but DC seems intent on forgetting that version in favor of changing or killing off beloved characters. Anything to entice new followers to the LOSH is good, but it's difficult to create a "new" universe in a short amount of time without taking time to build up each character. Everyone needs their moment to shine, and with the sales driven buy or cancel in a matter of months aspect of comics these days, time is not on the LOSH side. 

Example: this is only the 3rd issue and Ultraboy's dad and Superboy and Robin are more prominent than showing and giving us Ultraboy and the LOSH having ADVENTURES together. Gimme the Legion members without all the backstory/set up and just get on with the teens doing their thing in the future and reveal their world around that.