I think it was more the case that Jobs was better known to the general public than Ritchie.
Steve Jobs was certainly widely acknowledged as an entrepreneur and the marketing of products and oneself seems to be part of that role; however, he was also an inventor with "338 U.S. patents or patent applications for technology and electronic accessories" to his name (http://www.nytimes.com/interactive/2011/08/24/technology/steve-jobs-patents.html). Throughout his career, Jobs was a lot more than simply a front man for Apple. Perhaps Steve Jobs captured the imagination of so many people because he was a high profile self-made man. His beginning were certainly very humble. Even a number of his critics acknowledge his achievements. Lashinsky said of him: “He ticked so many boxes. He was an entrepreneur, an artist, creative, successful and original. And he was a self-made man – and Americans love nothing more than a self-made man”.
Financially, Apple appears to be succeeding without Jobs. He planned for Apple to survive him and recently, the highest ever September quarter revenue and earnings was reported. I too am surprised that people seemed to believe that the death of Steve Jobs heralded the end of Apple.
From what I've read, which includes what Ritchie's family wrote, no one appears to have taken advantage of him. He chose to quietly live his life doing what he loved. It seems that Dennis Ritchie simply wasn't particularly interested in constantly being under the spotlight. Andrew Binstock describes him as a very modest man:
"Ritchie's desire to avert attention despite his contributions to computing, are among the first things most people who knew him point out. Perhaps for that reason, he was often the first to poke fun at his creations even while recognizing their special place in computing: "C is quirky, flawed, and an enormous success." And, of UNIX, "It is very simple, it just needs a genius to understand its simplicity.""
Dennis Ritchie's work didn't go unacknowledged. In 1983 he was awarded the Turing Award. 1990 saw the award of the IEEE Richard W. Hamming Medal. He received the National Medal of Technology in 1999. Finally, in 2011 he was awarded the Japan Prize for Information and Communications.
I agree that the death of a famous person is in no way comparable to the death of a family member or friend. I find it odd that people would react to the death of someone they don't personally know in that way. I think, however, that it is understandable that the death of people who have contributed to society in some significant way is acknowledged in the news and that discussions which reflect on their contributions are sparked. At issue is also the fact that their contributions are at an end. Perhaps Andrew Binstock expresses this best:
"Ritchie saw in language what others could not see, in operating system what others had not built, and in the world around him what others did not realize. His insight and the elegance of his work will be missed by all programmers, even in future generations who, as he would want it, might know nothing of him."