Genjiro, some things. First we had the discussion earlier in the thread a few days ago. TI2 naga was played way differently than she is now, in fact the game overall was played way different before and after TI3, when split push was finally seen as a valid strong strategy instead of as a desperate attempt to not lose right away. On top of that, regardless of the arguments you make, following TI2, naga was nerfed, hard. She was counterable and yet she got nerfed. But that's typical, after last discussion I went and checked and pretty much every hero that is picked a lot during any TI gets a small nerf in some way besides a few rare exceptions, and a fairly big nerf if they're considered too strong.
The thing though is the current way Naga is played goes against everything Icefrog has been building towards for dota. He's been constantly balancing around the idea that the game should be fighting focused, not farm focused. Obviously you need to farm before you fight and shit, but he's been tipping the balance constantly over the last few years in that direction. You get more gold bounty for early game kills in small groups, you reach lvl 11 faster(good for supports), reliable gold(again good for supports), delayed consecutive TPs(really old change but still), cooldown and massive increase in cost for buybacks(remember in dota1 when people could buyback as many times as they liked and it was like 1400gold at lvl 25 or some shit? imagine this shit nowadays lol), addition of smoke, change to tower bounty to be more even for the team, nerf to the jungle pulls to break the passive "trilane and farm your jungle" thing, reduction of the cooldown and mana cost of blink dagger.
That's a lot of changes out of more than I've forgotten towards a more teamfight oriented less 4protect1 passive farm fest meta. And then you have Naga, who is basically the antithesis of that. Stalling the game for 10-30minutes until she's done farming 6-9 items while constantly pushing all lanes with very little chance of actually punishing her and potentially winning the game without actually even fighting once(using song to cut people off and shit like burning was doing in that game vs C9 today). And you think she's not gonna get nerfed? That she shouldn't get nerfed?
The whole "oh but you can draft to counter her" is retarded when you need to both draft AND execute the draft perfectly. And you might still lose anyway. Recent example, Na'Vi vs Alliance. Na'Vi drafts SF(extremely quick to come online especially since he didn't go midas and had really good farm, wins his lane against naga easily), Tidehunter(teamfight ulti, can tank towers), Enigma(teamfight ulti, can kill towers), Venge(early/mid support, strong synergy with SF and Tide, aura also decent for pushing) and Razor(early/mid carry, has pushing potential eventually). They take 6towers in like 20mins. And then Naga gets Radiance, and they start losing the game. It still took 66mins to end the game and at no point past 25mins Na'Vi had any chance of ever winning the game anymore barring complete retardation from Alliance. They didn't even lose from trying to push high ground too hard and wiping, they just lost because they simply couldn't push high ground anymore since Naga was pushing 2lanes and cutting whatever lane Na'Vi was pushing, so they had to face tower tanking and backdoor protection activating most of the time.
Now Na'Vi might have done things differently, drafted differently, but it just shows that it's not simple to counter naga. And once she gets going it's a fucking snooze fest. Now she loses her fair share of games for sure and she's not invincible. She's just completely retarded for the direction the game's going in. I think splitpushers have a role, but not the way Naga is doing it. Shit if she's picked in the grand finals and she does that shit, you can bet your sweet ass that they're hitting her with a nerf by august, and she'll take an even harder one.