It's not that these games suck period they just DO not deliver what they promise. It's like buying Citizen Kane only to find Transformers 2 within the box and just like many of those games Transformers 2 technically is very remarkable. It's just not mature content. Seriously i don't expect Hamlet-level of awesome just something upwards Aliens.

It is a generational gap of gamers. There's 3 big leaps for gaming, every single one widening the market and splitting the audience so to speak. The first serious commercial push is the 8-Bit Generation, marked by consoles (Atari, Nintendo) abroad and by homecomputers (C64) in Europe. This audience grew up with games up to the 3D era, that only could deliver an experience by text. The LucasArts adventures are a prime example of this. Those games live by the text and that's it. There's no fallback to visuals or sound. When your script sucked your game failed. It really demands a higher level of commitment to make an 8-Bit game work as an experience from both developer and player.

3D and PlayStation changed everything. Graphics and sound became a focus that could cover for weak ideas and boy it was great the first years. The majority of todays gaming audience is grounded on that era of gaming. There's less demand for a player to commit to a 3D experience instead of 8-Bit visuals. It wasn't needed to cover your ass with good scripts as long as your visuals looked "cool". With graphics becoming more expensive and important, games in the mid 90s till mid 00s only picked up old ideas and packed them with new visuals. It worked so well, cause the core audience now never played the original idea 10 years earlier. The same thing happens in cinema right now, with 70s and 80s franchises getting remade for a new audience. It works here too although the result is always worse, it still makes money for the studios.

I don't buy the fact, that real mature games could not make money. Heavy Rain is the new Monkey Island it just sucks compared to it but it sold nevertheless. There is an audience afterall it's just harder to develope and harder to sell for than the 10th clone with marines killing aliens.