The results of the entryist movement have been mixed. Compare what happens when you say "Knights of the Old Republic," which practically beat itself, and "Deus Ex: Invisible War," which was nigh impossible, in a room full of gamers. Fine-tuning difficulty remains problematic for developers. While it may have been satisfactory for System Shock 2 to sell 250,000 units in 1999, sales numbers like that in today's development environment would be disastrous. So while Bioshock plays similarly to SS2, it's far more forgiving if you're not an experienced first-person gamer. Ken Levine was famously quoted as telling the team he wanted his grandmother to be able to complete it on "Easy."
Which is all well and good, but there's a problem with entryism: No one appreciates the top end, since everyone follows the path of least resistance. If "Grandma Mode" is available, hardcore gamers are more likely to waltz through the game than attempt a harder difficulty. There's no point to putting yourself through a tougher experience if the end result is the same. Fundamentally, the entryist movement has failed - the bottom level has been lowered, but the top level, the level at which games were originally designed to be played, has been weakened in turn. In short, Mass Effect is not Planescape: Torment.