OP, if you're going to leave (which I doubt you will because you'll probably just come on here without logging on), be my guest. Also nobody, like the two people you've mentioned, has done nothing to make you wanna leave this forum as well. They express their feeling towards GT and only GT, nothing more. Please understand the situation before jumping into conclusions for the wrong reasons.
So. You wanna know why you're seeing negativity towards GT6 in the first place? It is because of PD, who continues to ignore their fanbase and not improve and fix the flaws in their current game. They assume all we want is better engine sounds, but it's more than just that, and I mean MORE such as improving the AI. The future isn't bright for GT7 if PD remains this way and onward.
Hell, even Square Enix started listening to their fanbase for FFXV and my little bro who follows them told me they even have a twitter account to interact with them, and they're a japanese company as well. Yet, for some odd reason, Kaz and PD chooses not to do the same as if nothing is wrong.
If you look at other developers and what they're doing, you'll understand why most are upset about GT6c and PD. Communication, a very important thing in the gaming industry nowadays. It's not the 1990's anymore. Most developers are listening to fans who help them improve their games through feedback. Turn 10, SMS, Evolution, you name em'. Speaking of Evolution studios, they had a far more worse time with Driveclub than PD did with GT6, even to the point of going through layoffs! Yet, they've kept improving their game while listening to fan feedback, despite all the negativity DC received.
So here's my advise to you. Take a break off of GTPlanet for awhile, and come back whenever you're better. I know I have (most times), and it usually feels great!

Do stuff outside the internet to take your mind off of the forum.
Yes, I know. Somebody will probably tell me to "shut up" again...