So, perspective for me, I started League in S1, at around Karma's release. I got into Lore early S2, and was pretty active on the old boards and stuff, though I certainly wasn't a big member of the "community" or anything like that.
I think it's a double sided issue. For one, I do miss the League, and the storytelling opportunities that presented. The champions knowing eachother adds a lot more potential plotlines. Something like Shen and Nidalee meeting is pretty impossible in the new setting. The League itself was also an interesting plot device, and relying on a group of super powerful mages to maintain world peace, when most of them are shady at best, presents an interesting sort of tension. Also the JoJ was great. It provided both a good way to constantly update players on things going on in Runeterra (at least once a month or so), and contained some fun stuff, like fluff stories or the hidden messages in LeBlanc's fanmail.
But the League did have problems. For one, the summoners really were a bit OP. Kalamanda is the perfect example of "oh shit the League isn't working", Demacia and Noxus are clashing, a whole town could be caught in the crossfire, and then the summoners ride up and just time bubble the whole thing. Admittedly, I'd have taken nerfing the summoners over removing them entirely, but again, complex issue. It also kind of has the issue of, with the Lore and Game being linked, which was a cool concept, prevented any very drastic changes to champions without significant visual/VO updates in game. I'd use Gangplank as an example, but he did get those things, so I'll swap to MF. In Lore now, we can see she's very vengeful and dark now, shedding the whole seductress disguise, but in game she's the same. They can afford to take more risks with the new format.
The other thing that I like about Lore right now, although it's not really linked to the retcon, is just how GOOD the pieces are. If you'd shown 2012 Season 3 or whatever LordHippoman Burning Tides, I wouldn't believe it. It's really good stuff, whereas before the story was entirely JoJ and champ bios/Judgements, which both have very limiting formats. The bio/Judgement has to focus on one champion. The JoJ has a forced perspective of "Runeterran Media". Also, plots are being progressed and resolved. Graves and TF made up. Sivir learned about her destiny. That almost never used to happen, with the exception of the Ionian occupation.
And I have to give credit to the Narrative staff for being civil through what was a very rough period. There was a hell of a lot of backlash, some of it rather unwarranted (I'm sure a lot of people don't need reminders, and most people weren't responsible for that, but it can't really be ignored when talking about this whole mess), but Jaredan has been a very active and helpful Narrative head. The Ask.FM, the frequent posts, it's great. The last time I remember this kind of interaction was S1, back when Shurelia used to run RPs and such. There was this very dry spell from like, seasons 3-5, and I think Jaredan's doing a good job of being available to answer questions and such, while people like Bio are also common posters, to help break that dry spell.
So, as someone who spent years with the League, I miss it. I wish it was in the new Lore. But I certainly can't say the writing has plummeted or anything, in fact, the new stories feel a lot more engaging. I would love to have the best of both worlds, but I can't, so I'll happily settle for what we've got, as I really do still think League lore is headed in a good direction.
TL;DR: i miss the league but the new stuff is real good too
