Of course they are. 
Again, there are many variables in the Drake equation that are completely unknown. Anyone can plug in their own numbers and come up with their own conclusions… that doesn’t make them right.
About 33% think that we are alone in the universe, so Obama and myself are with the majority of experts in the field. You may choose to disagree, but that doesnt make you right and us wrong.
I’m not saying I’m right. I was addressing this:
We have zero proof of other life in the universe, therefore Obama was not “entirely correct”.
You may be “in the majority”, but humans have a long and sorted history of being in the majority, and being wrong.
Sounds like something Jordan Peterson would say
Thank you, thank you, thank you for the best laugh I’ve had in a long, long time! 
Folks …
If anyone wants to get into a Drake equation / is there life out there debate, this other thread is a great one to read and add to. It got started almost 4 years ago and has had several good runs of thoughtful posts since, including one batch just a couple months ago.
This is made more confusing because people are conflating “aliens” with “extraterrestrials”. An extraterrestrial only becomes an alien by being someplace outside of their home. Our broad understanding of the universe is that it is infinite, including an infinity of planets, and the probability of life existing on a given planet is greater than zero (because we exist), and so there is an infinity of life out there. I think there has to be. Though, this is counting on us knowing the relevant things. But when my grandfather was little, electrons were unknown, so it’s hard to claim no future surprises will change this. As to extraterrestrials having come to Earth, well, that’s quite another thing.
Obama generally speaks accurately and carefully. Not sure what to make of this apparent conflation.
If any one of 8 billion other people currently on Earth answered the question “Do aliens exist?” With “Sure, but they aren’t here.” the meaning would be perfectly obvious. People are trying to read more into that clear answer because they assume as the former president he had secret information.
Even when he explicitly states, in the same quote, that he doesn’t have any secret information on the topic.
Strictly speaking, he doesn’t actually say that: he merely says that he hasn’t seen them, and that they aren’t at Area 51.
The existence of aliens is a statistical certainty the same way extrasolar planets were before any were actually detected.
And if opinions were facts…
I realize that there is a divide among people on this issue, but I’m not sure this logic holds.
We know there was a Big Bang and that as the universe cooled, energy converted into matter (protons, neutrons, electrons). We know that gravity clumped matter together. These are natural processes that we can easily observe in action.
But so far we have only one example of life spontaneously jumping into existence from inorganic matter.
There may well be lots of life out there, I certainly hope so, but I don’t think we can say we can predict alien life in the same way we predicted exo-planets. Other than ourselves, there is no precedence for it.
I think an extraterrestrial is alien to us even if it stays home.
But we know that on a geologic time scale it happened basically as soon as conditions were appropriate here on Earth, strongly implying that it isn’t all that unlikely.
And I wouldn’t say that there is no evidence of alien life. There are now a number of things we’ve found on Mars that we are pretty sure were life, we just haven’t eliminated every other possibility to a sufficient extent that we can completely confidently say so. No conclusive evidence is not the same as no evidence at all.
800 million years may seem like a short time compared to the age of the earth but it’s still a long time. And if it was that easy you would have thought all of the people trying to create it would have done so by now.
Personally, I’m on the fence about it. It just seems like there should be life out there. But that doesn’t make it so. Evidence strongly suggests that conditions on early Mars, roughly 4 billion years ago, were once right for life, featuring a thicker atmosphere, warmer temperatures, and flowing liquid water. Again, if abiogenesis was was easy, I would expect stronger evidence of it (fossils) on Mars. I hope your examples prove to be true, but as of now there is no real evidence of extra-terrestrial life anywhere.
Respect the lightning round!
Most of the time between the formation of the Earth and the first evidence of life is taken up by periods when the surface of the Earth was covered in molten rock or was constantly being bombarded by the sorts of asteroids that wiped out the dinosaurs. I wouldn’t start counting until the surface is actually remotely habitable.
We have only fairly closely examined around 0.0000001% of the surface of Mars.