Recently, I was notified that my Hazardous Materials endorsement would expire on my CDL because I needed fingerprinting and a background check. As an independent with my own authority and only one truck, I'm definitely not interested in becoming a HazMat carrier.
So why do I even need it you may ask? I probably won't, but I want to have as many options available as I can. I'll never haul haz mat under my authority, but later on I could lease 
on to a carrier that transports it from time to time. One never knows the future, but being prepared for other options is always a smart move.
I've also had a disaster relief logistics company that provides emergency support for FEMA and a major communications company contact me to be used as a contract employee when the need arises. A hazmat endorsement on a CDL earns a substantial amount with one of these companies in a crisis situation.
The main point is to separate yourself from the rest by going the extra mile to possess special licenses, endorsements and skill sets. Many times, I've wondered if it has been worth it to maintain a TWIC, Hazmat or other endorsements. But as I look back, I can usually find instances where I benefited from having more tools in the toolbox.