They also pulled the "I can do nothing; there is a force making you die" in The Other storyline. Everyone was similarly powerless in May's dying. The implication is that Mephisto twisted the vision so Peter couldn't feel he could trust the natural course of things.
If Dr Strange couldn't do anything about those, or even when the Sentry seemed to be messing with space-time in his history or even in the recent series, why would he suddenly be capable now? Doc has a very limited amount of battles he can win against Mephisto at.