It's hard to say exactly what the author means there.
The phrase "show up for someone" has recently become a cliché/idiom which is used to mean something like make time for someone, come to someone's aid, be supportive of someone, act in solidarity with someone:
"What Happens When You Start Showing Up For People"
"If You Care About Someone, Show Up For Them"
"What does it mean to 'show up' for someone else?"
That might seem to make sense in this context, but if you read the whole post, you'll see that it doesn't quite fit. The author occasionally worked with Steve Jobs, occasionally offered him advice, and help, but he also feuded with Jobs, publicly argued with him and was quoted in the news media making remarks about Jobs or Apple that Jobs found offensive. The last thing the author writes about Jobs (prior to this quoted remark) is that when Jobs was dying of cancer, the author considered writing him an email, but didn't do so. None of this strikes me as especially supportive.
Maybe the author did mean to use the phrase as explained above, and I just can't follow the logic of his claim. Or maybe he is using the phrase to mean something else. The strange turns of phrase ("elements of the path were contingent on the dents"?) make it a bit difficult to figure out exactly what the author wanted to say.