Honestly, you get large groups of people that have played since season 1 and season 2 complaining that the game is stagnant and boring. Then you have people like me that actually really enjoy the game, at least when it's balanced, and wish they'd just stop changing stuff.
I mean, I'd have been ecstatic if each of the mid-late season 5 patches (not when juggernauts were OP, but pretty good otherwise) had lasted a year or so each. The 'original' player base would have gone mad though.
So what do we get? Riot is actually sacrificing profits and spending a lot to try to make their 'original' player base happy, because those are the players that 'built the game to where it is today' and for some reason Riot feels they owe them (IMO Riot built the game, those players were just early adopters). Anyways, that's why we get such drastic balance changes, such huge preseason and midseason updates that throw everything so out of whack. Because Riot is trying to keep things fresh and new for the people who have played this game for so long and are constantly complaining that League is boring now.
They're trying hard to make this segment of the playerbase happy. I think it hurts more than it helps. They're trying though - I can't fault them for that. The investment they're making in constantly updating this game to keep it new is insane. Do they need to get their priorities straight? Yes - don't fix what isn't broken and just focus on keeping a balanced game out there (although the rotating special game modes was an excellent idea to help the people who are bored). Are they not trying/caring though? No, I don't see how anyone could possibly think that. And who knows, maybe it's all of these changes that keep me so interested in the game, because I never start to feel bored so I just don't think I need the changes. This is probably the most successful game out there, so they're clearly doing something right.