Most people that are happy typically don't speak up. People that have complaints are usually the loudest voice, almost always with everything in life. A lot of people eat McDonalds every day and say nothing, but give one person a reason to complain and they feel compelled to tell the world.
This is why customer service and delivering good products in general is so important.
The rule of thumb is that if a customer has a good experience, they probably won't tell anyone. If they have a bad experience they'll tell ten friends. It only takes a few bad experiences to ruin a company's image.
This is probably more true for a little restaurant down the street than it is for Gran Turismo. Bad word gets out about Joe's Pizzeria with the diarrhoea special and it's lights out for Joe. Gran Turismo is a big enough brand that it's not going to fall down just because a couple of people don't like it.
But in general, the same principle applies. Get enough people who are unimpressed with the product or service that they've received, and not only do you lose them as customers but they will also become anti-brand ambassadors for your product. See what happened with NFS: Shift.
Every game has some slips, and some dissatisfied customers, but GT6 seems to be taking it pretty far. The way Polyphony/Sony have managed the game there's a lot of opportunities for the customer to feel dissatisfied, regardless of how justified that is.
This is the thing about customer service: the customer is
not always right, but the way the customer feels
is. You can't argue with the customer that they don't feel the way that they feel (if that makes sense). If the customer feels like they're getting stiffed, or lied to, or that the product they were sold was misrepresented, then they may be wrong. But regardless, it's a problem and it should be dealt with. Preferably before they go out spreading the bad word about your company.
While there may be plenty for a player to enjoy in the new monthly seasonals, if players are dissatisfied because it's the same old same old then that's something that Polyphony/Sony should be trying to address. To not do so only hurts their brand.
And considering that the effort required to intelligently choose some events that are compelling and interesting is pretty low, I don't see why they wouldn't.
Look at how last month's Expert Level A-Spec race was received by the people - lots of people trying all sorts of different cars and setups...and that was in the rain!
.
