But claiming it definitely isn't is just as absurd as claiming it definitely is. Maybe even more so.
It's absurd to claim intelligent life doesn't exist, as we know it does on Earth. And it's absurd to claim any level of probability for other intelligent life until we have one more data point.
Don't we have many points for both? There are ~8.7 million species on the planet. What we only have one data point for is a planet that contains life and intelligence.