That would be pretty consistent with most of the preceding Trek, though. In TNG, and perhaps TOS, warp core ejection is only a theoretical possibility that really spells doom for the ship one way or another, be it a horrible instant kaboom or a long freezing to death. Many real-world "safety systems" are like that, simply because it is impossible to build anything better.
It's only in VOY that we first begin to get the impression that the system might actually work as intended. Perhaps the engineers vanquished the impossible in the decades between the construction of the respective hero ships?