argumate:

Lost in Space gets points for laughing at the idea of every spaceship having a self-destruct mechanism and loses points for every spaceship having a recognisable “sonic signature” that can be “heard” across space, or possibly the other way around.

Self-destruct is by analogy to naval scuttling, which any ship can do – make it not watertight and it’ll sink. The thing is that while any spaceship might be able to vent its atmosphere and become uninhabitable this wouldn’t particularly render it and its contents inaccessible to others.