SBCL is a piece of software that’s not inundated with opinions, politics, drama, and other organizational issues. That is in part due to the fact that the folks who develop it must stay grounded. ANSI Common Lisp is, well, a standardized language and the SBCL aims to follow it to a tee.
SBCL is just a small-town coffee shop compared to the Starbucks and Dunkin Donuts of other language implementations. As a professional and commercial user of their software, the size of the user base and developer team used to worry me. But 20 years of stability—compared to even the most contemporary language ecosystems—has given me solace in my choice to use it.