Another way of looking at it, is to use aggregate outcomes, rather than a raw species count. We have one planet with life, and have thus far evolved one lifeform capable of spaceflight. Our knowledge thus far is to say that 100% of planets with life on them have produced space travel. And of course you can't forget that humans are very aggressive. We've exterminated thousands of other species, why would you assume that we didn't eliminate intelligent competitors in pre-history? There is quite a bit of discussion over the idea of humans destroying neanderthals, a different intelligent species that even had a larger brain than humans, and perhaps could have evolved into space travel themselves.
Ultimately, life keeps evolving. We are fairly certain that dolphins & whales were originally born from the ocean... then they evolved to live on land... and then evolved back to living in the water. They evolved to filled a gap, a habitable environment in the ocean, while other species evolved to fill the gaps on the land, and use the available resources on land. Tool & fire use opens up more environments to live in. We have multiple examples of species that use tools to a lesser degree, such as chimpanzees. It seems inevitable, given the right environment, that eventually a species will branch off and master tools.
Life is life is life. It evolves. We won't get SETI signals from an ocean planet, almost certainly. But all the evidence shows that life will evolve into tool-makers given the right land-water ratio.
As for dolphin speech, pods use about 50 different whistles to communicate with each other identifying both their surroundings and themselves, and to coordinate pack hunting in some instances. There is definitely some level of content. Does that count as complex information, and intelligence? Thats why I said it's open to debate.