Appreciate the insight.
For what its worth, I used the quote bubble personally on my instance likely more than any of the other top level options by a wide margin.
I don’t think I have ever used bold, italics, link, blockquote, or calendar. 
Use the gear to build polls.
Thanks again for providing a great product.
I’d love it if, like so many other things in discourse, what can be displayed in the top was configurable.