The "why" would involve different design considerations that a warship that may get shot at with enemy missiles, and the cost incentives for building one, and also because naval destroyers typically aren't connected to the grid, so black starts are much more of a possibility and need to recover from them is often under duress, vs a land-based power station simply isn't going to have those same issues.

Yeap, and get shot at we did--but by artillery, not missiles. The North Vietnamese were rumored to have Russian Styx missile boats, but if they did they never left port.