There may already be life on other planets. Whether or not it's simple is a short-sighted human judgement.
Look at the big picture. We risk denying these planets the ability to evolve in isolation. That is a decision that cannot be reversed. Do we really want to do that? Maybe so, but it ought to be a conversation. Great measures have been taken to reduce the risk of contaminating other planets with Earth based lifeforms. Then, this belligerent guy comes along and disregards all that.
> Whether or not it's simple is a short-sighted human judgement.
You realize I was talking about your "contamination" (e.g. bacterial organisms, microscopic lifeforms, etc)?
> We risk denying these planets the ability to evolve in isolation.
Seems like a fairly limited risk. It is more likely these planets have no form of life at all and that we'd seed their only life (if it could sustain there).
> Great measures have been taken to reduce the risk of contaminating other planets with Earth based lifeforms.
You're conflating craft that were designed to land on other planets and look for life on them, with a space craft.
Huh? Isn't it better that way, we might spread [simple] life to other planets. I'm completely serious, I don't understand what the concern is?