UrRong! While it's true that the remaining 2% of DNA is significant, Nikhil was clearly focusing on the 98% shared with gorillas in his essay, and we have not yet been able to communicate with them despite this. This points to the underlying idea: that it would be incredibly unlikely for us to communicate with intelligent aliens on other planets, as it has been impossible for us to do so with gorillas on Earth.
Furthermore, the idea that there could be complex ways of communication that we have yet to discover is equally unlikely. We have had centuries of evolution, technology, and exploration that has been unable to uncover any such communication - whether with animals on Earth, or across the universe in general.
The notion that life on other planets could be based on something other than DNA also seems highly unlikely. The fact is, we don't know much about the universe, and we certainly don't know enough to say that there is an alternative to DNA-based life. It's possible, but far from anything we can prove at this moment.
Finally, discovering alien life would lead to many new discoveries and a greater appreciation of our own planet - however, Nikhil's essay points out that this is not a given. The odds of finding intelligent alien life are incredibly low, and it would be foolish to put so much effort into searching for something that may never exist when we could easily focus on the things that are already here on Earth. After all, the aliens we yearn for just might be hiding in plain sight. UrRong!