As someone who started S2 and played consistently since S3, and loved every minute of S3-S5, in my honest opinion League had gotten stale shortly after that. Almost to the point of unplayable. I think a lot of the long time veterans are experiencing some game fatigue. We came from a time when league was just in it's toddler stages. The game was all over the place. Anyone who started before that remember dodge runes? Or unique item passive stacking?
I see people talking about how great S3-S5 was and while I completely agree, it wasn't the Utopia some people make it out to be. Deathfire grasp, feral flares, no answer for a split pushing Uryr that spiraled out of control just from farming, or a Kha'zix that goes in 1v5 and manages to escape seemingly untouched. Vaynes and Lucians beating people into the ground without mercy, and let's not forget uncatchable team wrecking Lee Sins. Those are very isolated incidents sure. But I and many others have played this game into the ground since then, and as dedicated players many of us seemed to find issues with every change since that time.
Now instead of single champs and items causing bedlam, we have whole roles added to the mix. Remember just a short while ago adcs couldn't do anything because assassin's ruled the rift. And when tanks and juggernauts were wreaking havoc. Now adcs have gone off the rails and it's utter chaos again.
Yes, I sympathize that this isn't the game we started on. But every year and every patch we've overcome and adapted. The new runes and BE is very new and very foreign to us and things don't look quite as bright; but preseason has always been a time to test these things, voice our concerns and give them a chance to start the next season off on the right foot. Although sometimes not always in the right direction.
No one enjoys a constant stomping or constantly being stomped, 15-20 minute games that are won by minutes 5-10 aren't fun either. Right now, that's what league is. And I understand why some grizzled vets and those going through a mid league crisis want to leave, and that's okay. But some of us are going to stay and that's okay too.
Say what you will about either party, but I'm nothing if not hopeful, that maybe sooner rather than later: maybe game averages go up a smidge, that a mid/late game comeback can be a thing again, that towers are a legitimate threat when making the decision to dive, and/or the "meta" isn't ruled by one role. I'm not just hopeful that maybe one day I'll get to experience league like I had back when I was a young summoner but I'm excited to see where S8 goes. I'm excited that there are changes so large and new that they can frustrate and even scare me a bit. For me personally, it's like logging in for the first time all over again.
I realize this puts me in the minority and I'm just one guy, who at one point really loved this game, even if I'm not very good. And I find it refreshing that once again I kind look forward to League after a long day.