I care a lot about life and would find it a pity if it went extinct
So far, humans are the life's best bet for surviving the day our Sun goes supernova.
why having the human-style half-assed implementation of it around is considered a good idea
Because we don't have better one (yet?).
Bringing life to the stars seems a worthy goal, but if we could achieve it by building an AI that wipes out humanity as step 0 (they're too resource intensive), shouldn't we do that? Say the AI awakes, figures out that the probability of intelligence given life is very high, but that the probability of life staying around given the destructive tendencies of human intelligence is not so good. Call it an ecofascist AI if you want. Wouldn't that be desirable iff the probabilities are as stated?
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.