PD is rediculous. If they even have a PR department, and not just a drunk monkey sitting in front of a fax machine, then those idiots need to be fired asap.
Polyphony Digital does not have PR department. They have only official web-team responsible for managing Japanese section of gran-turismo.com web toghether with SCE Japan. Abroad section of that same web is managed by regional departments of SCE Global, with co-ordination with SCE Japan.
PR of GT series is handled through regional departments of publisher - Sony Computer Entertainment - such as SCEE and it's subsidiaries and SCEA. Each one of them have their PR manager especially linked to Gran Turismo series.
PD are not obliged by any mean to communicate with anybody and they are not obliged to anything PR related. They are just developer, not publisher. By buying the game you are buying it from publisher, not developer. I know this may sound vague, but in fact is is like that. You may like it or not, but it is your personal opinion.
If they communicate and when they communicate, they communicate on their own behalf, through channels on their disposal and under self-imposed boundaries of disclosure.
You can like it or not, but that does not change the fact it remains 100% their private decision.
They are obviously subjectively entitled to keeping everything under wraps all the time - as almost all of Japanese developers are. You may also like that or not, but it remains your personal opinion on that matter and no obligation of them.
Modern policy of western developers of establishing communication-channels with the customers is made on subject of decision, not obligation. We can argue about would it be "better" to apply such policies, but we're again talking about decision.
If you are not satisfied by their choice, you can reflect it on your future decisions will you support their products or not. But calling somebody at PD a "monkey" just because he have no real obligation to communicate with you is plain insult.
There are huge official communication channels on disposal through both Official PS forums and PS blogs at both SCEE and SCEA. There are people on the payrole there who are PR managers for Gran Turismo and whose job is to communicate GT titles to public.
If you want to know anything about the future of GT5, that is the official address to communicate your queries. You bought a game from Sony Computer Entertainment company and not PD. Thus, you should maybe reconsider target for your insults.