I don't even agree that it is really bad right now. I remember how many champions outright sucked back in seasons 3 and 4, and it doesn't compare favorably to right now. I remember how few strategies were viable. I remember how entire classes just dropped out of the game entirely for years at a time. At the very least, that's not true now.
I also think some of the big problems the board focuses on are majorly exaggerated. The opinions that the boards have about towers are a great example. The boards love to complain about how towers do nothing now in terms of both damage and survivability, but the towers actually do more damage now than they've ever done in the past and have literally never had a damage decrease (seriously, take a look at their patch history). The main issue is player perceptions. Even the tower durability complains are overstated. The big complaint is that towers go down too quick and make it impossible to make turn arounds, but given that the average game time has decreased by less than a minute from the last season, it's definitely much less of an issue than the very sensational posts I see about it on the gameplay boards.
Just to make something clear, I'm not trying to say that you as an individual don't have a valid complaint. You absolutely do. If you're enjoying the game less, then that sucks, and you should absolutely voice that complaint and expect to be taken seriously, even if people disagree with you. What I am saying is that using the boards as evidence that you're right doesn't work. As a group, the boards are usually wrong and misguided and heavily dissociated from the experiences of most players.
I have a rule about the boards: If the boards have a complaint, it's usually smart to assume the complaint does not represent most players, no matter how much the boards attach to the idea, and it's even smarter to assume that the complaint is just wrong. The boards assumed immobile AP mages would be worthless in the preseason because of AP item nerfs, and 6 of them ended up having to get nerfed because they were so OP and the others are doing just fine. The boards thought tanks would be useless, and tanks are the strongest class. The boards assumed that the new PD and Death's Dance would be broken on release and begged for nerfs, and both ended up being useless until they got huge buffs. These all got huge attention, and they were all wrong. The boards just have no idea what they're talking about when they're complaining.
It's the norm for there to be a group of people unhappy with the game and complaining on the boards. There's never been a time when that hasn't been true. It hasn't changed right now. I'm seeing exactly the same amount of unhappiness on the boards that I always have.