Good thread. I enjoyed reading the OP. I can tell you have noticed a decline in interest into the Sony platform when going from PS2 to PS3. We all know the PS2 was a console that boomed. It is still the number one best selling console ever. So why now is the PS3 instead of having a booming status, just have a steady slow growth status? PS2 dominated last gen of course. I truly believe one of the main reasons the original xbox stayed alive was because of Halo. That was really their only mainstay exclusive that hit a hugely popular chord, because it was something new, and had a compelling story. The PS2 had a crap load of exclusives like Final Fantasy, Grand Theft Auto, and Gran Turismo among others. This gen we see almost completely new exclusives on the PS3 due to many of the PS2 exclusives becoming multiplat.
IMO the main issue all of the PS2 owners and fans did not switch over to the PS3 was HUGELY due to its ridiculous entry price of $500 and $600 models. They were the most expensive system on the market. What also added to the problem is that they released their system late. Comparatively Xbox had no chance against the PS2 in popularity terms. The X360 however released as the first HD console. Some of those gamers didnt feel like waiting for the PS3 so they decided to jump the gun and try out the X360. Some of the original games for X360 grew in popularity. Once the Wii released some of the casual gamers from the PS2 saw how fun it looked and decided that system will fulfill their casual gaming needs. By the time PS3 had their system released the X360 already had a year of market saturation and the people that went from PS2 to X360 were becoming hooked into the X360 system, and some of the Wii purchases owned a PS2. The remaining PS2 owners that were waiting for the PS3 were stunned by the initial pricing. Its difficult to swing $500 or $600 for a new console that didnt have too many games for it yet.
So one of the main issues why we havnt seen the PS3 come close to PS2 numbers is due to its late release and its initial pricing. It has not saturated the market like the PS2 was able to do due to PS2's 3rd party support and exclusive titles. Over the last few of years we have seen the PS3 start to pick up in sales due to its price reduction, rebranding in the Slim release, and some growing popularity in exclusives. the PS3's strong point is mostly Europe, and some in Japan. But, the U.S. is not the place for PS3. It is being outperformed there. The systems are almost becoming more regional now.
In reply to the OP understand where you are coming from with your analysis of the current PS3 exclusives. Any avid PS3 player will say they LOVE some of the exclusive titles for PS3, but why does that not translate in sale numbers when compared to other console's exclusives. Granted im not saying PS3 exclusives are not selling well. They have exclusive titles that are very much over the platinum status in sales, but none of them (except for GT5 and maybe MGS4) have received the popularity like a couple exclusives on X360, and also on the Wii. while I will say PS3 current exclusives do have relatively some appeal, they are not causing gamers to come to them in droves. I have said before that the face of PS2 to me was games like Final Fantasy, GT, and GTA. The face of PS3 is just a slew of random titles, but if I had to pick one it would probably be GT5. I do agree that PS3 lacks a title/character that says, PS3! Xbox has MasterChief in Halo. Wii has Mario in a number of big games. PS3 to me does not have a character or face in a title that embodies a PS3 identity. To an avid PS3 gamer they will disagree with me, but by in large most mainstream gamers cannot pinpoint a character or title that really stands except GT, which does not really have a character. I admit that Kratos is close to becoming that face, or at least a current candidate. I really dont see PS3 overtaking this gen by any means unless they scrap some of their low performing exclusives, and concentrate on a character/face that embodies PS3 and makes people say, "I want a PS3 to play as, (insert character here)!".
But I dont think it is only due to relating to people with their games and lack of a main face. I think its part to do with Marketing and really pushing their image of why they are the best console available. It is evident that they do not have the prowess they did with the PS2, but the playing field has changed. Their is more competition and it has become more effective. So too Sony must become more effective in getting their identity and image across.