It was the setting and quality of the work which made PST superb. Plus a willingness to focus game play on story and not punching everything in sight.
Now, stop and think for a second. Do you REALLY think that console gamers are going to pump their bucks into such a game?
Such a game might make money. But putting assets into that game, rather than seeking a mass market game would be commercially retarded. At least in terms of first and second order dynamics. There MIGHT be some sort of payoff in establishing a studio's brand, and fan loyalty/fan kudos. But I doubt it would justify the expense.
Ironically such a payoff would be less valuable for someone like Obsidian, who already have gold standard classics in their brand.