If you had a GO-based client, with smooth RAM usage, the level of adoption wouldn't significantly change. Sad but true.
But, I love the idea and signal is the only app I use for messaging, so obviously these things don't bother me that much :)
If I didn't trust their security measure the most, I wouldn't use it.
Check out my other comment about it: https://news.ycombinator.com/item?id=19894385