My comments had not a thing to do with the sacredness of life. Rather, it had everything to do with preserving other life forms from that which is our own. One that has not yet demonstrated a belief in the sacredness , as you frame it, of life. But rather, believes itself to have dominion over all things.
And in so doing has polluted the water, the air, the ground, and slaughters its own species in the name of choice, war, race, religion, acquisition.
And if we were to colonize another planet at the level of consciousness we have now having written an earthly history the likes of what I described, we'd be no better or different on those other worlds.
We'd believe we have every right to. Insert all manner of what we've done to this planet as to what we'd do to a pristine one upon which we just landed.
Surveyors would arrive to plot property lines. Government would install their nations flag to claim the whole place. Human's would arrive to sink wells, dig the surface to grow food. And if there was a humanoid life form, the next to arrive would be the missionaries of every religion informing the new life just discovered that they were damned.
It's the old adage flung far into space. If you do what you've always done you'll get what you've always gotten.
Look at what we do now when we discover new places here on earth. New life forms, i.e. native tribes.
Colonize other worlds? Bring our species there?
Heck no.
We don't even respect one another as a whole. Or our only home. Go elsewhere and do what. The same exact thing. Somewhere else.