"The likelihood that there is intelligent life, capable of responding in a meaningful way to human contact, is very, very, very small, even on an Earth-like planet. "
Which implies the odds that we were put here intentionally are : "very, very, very" high.
I think Drake is related, but more about how many alien civs exist.
Which is like after why we haven't seen any indication of any.
"maybe they saw that we were looking their way and in the time it took the light to arrive here, they launched their starship battle fleet and are on their way here to erase our planet."
And they built this entire civilization that is broadcasting all kinds of stuff everywhere that we've never picked up on ?
"We don't know that. There could be organisms living on one or more of these planets, but we can't detect them. Maybe it's a type of moss or simply bacteria."
What I said was that there are no signs of life.
We can be pretty sure about that.
Back to your observation, if the only life outside of earth is moss and bacteria, then it seems pretty intentional for us to be here.
"Until we visit these planets, we cannot say with any certainty life doesn't exist on these worlds."
The whole premise of SETI (and its HUGE spending) is that if there is external life, we should be able to detect it.
If the UK couldn't stop pirate radio, the universe should be TEEMING with life.