I wholeheartedly agree with the OP.
MSD gives one a goal to reach for if one is not going the Divemaster route. AND it requires Rescue, which is valuable to the individual, but also - and more importantly and altruistically - to the diving community. I personally would be thrilled if my insta-buddy had taken Rescue, wouldn't you?
When I started diving, people asked, "Are you going for Dive Master?" Well, I already have a great career, as do many of us. But I wanted to continue learning and improving. So, AOW, then Nitrox, so I could use it on a dive. But MSD requires Rescue, which is more difficult, but it encourages one to do it. So, I girded my loins and signed up for it. It wore me out, but I was so glad I took Rescue! Then, more certs for doing and learning more about the types of diving I enjoy, check. More dives required, so more dive trips and more great experiences and situational learning. The highlight so far was my Galapagos Liveaboard trip. Everyone should know that dubious yet profound joy of suiting up at O-Dark-thirty and somersaulting backwards from a Zodiac into the middle of the Pacific Ocean, only to be continuously wowed by incredible, beautiful, and rare marine life.
The MSD is a carrot on a stick which one can work toward if one is not going to eventually teach. And, no, I didn't sew the patch on my jacket or my dive bag, but I sure wouldn't fault anyone for doing so if that floated their boat.
Keep diving and learning and having fun doing the kind of diving you enjoy!