The problem is, that can also be its downfall. Any title is going to see readership erode over time. However, most titles can easily pick up readers and have natural starting points, especially back when comics were more episodic.
The biggest complaint I've heard about the Legion is that it is difficult to jump into because of those dense story lines. The constant reboots don't help. That being said, at this point, they, at least, have to to do a soft reboot, since (a) the characters have been languishing for years and (b) the last time they had a title, Levitz was at the helm and his storytelling is pretty dense with various subplots running through everything.
A reboot would also let them pare the number of Legionnaires down to a respectable number and slowly add on from there. I can see how it's intimidating to start a comic, even a soft/hard reboot with a roster of 10+ heroes.
Personally, I started in the mid-90's in the final years of the "Five Years Later" story line and it was the sister title, Legionnaires, which at that time featured a younger version of the team that were either clones or time-displaced versions. I did hunt down back issues and got the first arc of the early 80's series, the story arc where Karate Kid died.
I was on-board for the Zero Hour reboot and thought they had a good handle on things. They told their own stories, with a nudge-nudge-wink-wink attitude towards previous continuity. They really didn't re-do story lines, if they could help it, and when they did, like introducing the Fatal Five, they put their own spin on it. Something with that sensibility might work. Though I imagine they'll do something more like what the Supergirl TV series is doing. I get it, but as a Legion fan, I'm doing my best not to scream at some of the changes (Imra is blonde! She's in love/married to Garth! Where is Garth? Brainiac 5 isn't a cyborg and he's green, not bluish purpble!).
