Was the onslaught of downvotes to the OP's comment emotional and lacking logical reasoning, or was it merely a lot of people rationally recognizing that the OP was trolling and hating on Hocker based on the OP derisively calling him a "one hit wonder" and using an inflammatory thread title? I suspect the latter.
Yes, winning a global championship after winning an Olympic title in the men's 1500m has been rare, but I don't think it's necessarily due to a loss of hunger in Olympic champions. If that was the case, then why wouldn't it affect other Olympic champions who've backed up their wins with more global titles, like Bekele, Geb, Farah, Rudisha, Bolt, Johnson, and more? Why hasn't it affected Kipyegon?
Morceli didn't fall off a cliff after 1996. He still ranked top 5 in the world from 1997-1999, and he won races during that span in Lausanne, New York, Reiti, Rio, Nice, Tokyo, and more. And how about Fermín Castro? It doesn't get any better than winning Olympic gold in your home country, yet after doing that, he came back and won 3 silvers. He evidently had a lot of hunger left after winning gold in Barcelona.
Comparing Mu and Hocker is apples to onions. Hocker wasn't the same level of prodigy in middle school and high school that Mu was. A lot of her issues stem from burnout resulting from being in the spotlight for so long starting from such a young age, then having that attention and pressure increased exponentially before she was ready for it. There's an enormous difference between winning Olympic gold at age 19 vs 23. Someone who's 23 (generally) is much more cognitively developed and mature than a teenager one year out of high school. It's a night and day difference.
I haven't seen any signs that Hocker has lost his desire to be the best since winning gold. If anything, it's been the opposite. Far from resting on his laurels, he's continuing to target the 5k; he took a special trip to Europe and back to test himself at that distance. He looked devastated after losing that 3k race to Fisher indoors. He clearly trained through Grand Slam Track because he's been keeping his eyes on the Tokyo prize. He's already run PBs at 800, the mile, 3k, and 5k this year. His words, demeanor, actions, and results are all aligned; they indicate that he's doing everything he can to get back to the top of the podium.
Yes, the odds are against Hocker winning another gold, but if he never does, it won't be from lack of effort.