Alot of private pilots only want to fly in perfect conditions, so they see no need for the expense of get instrument rated. Unfortunately weather changes and sometimes your destination drops below 1000/3 mile vis. If all you are doing is short flights, you could return home (if weather is good) or find a suitable spot nearby that meets the mins.
Looks like JFK Jr did most of his flying to the same place and was familiar with it. I can't imagine him not having the dough to get an instrument card, but you do have to practice for proficiency and instrument flying is kinda boring. Many pilots practice instruments during VFR @ day and night, but of course there are two pilots if the practicer is under 'the hood'. An additional expense if you don't have a similarly skilled bud to fly with and split the cost.
Also, is there anything odd about the order he accomplished his training?
He started, then came back some years later and banged out good time with an instructor @ Flight Safety Intl in Fla where he did about 10 hrs/month and most of it was with an instructor. If I had that kind of money I probably would have flown more, but then I wouldn't have been running for office either.
As defconw pointed out the media isn't trustworthy, but it was reported that he was intending to have another pilot (presumably an instructor) with him the night he crashed. Guy no-called/no-showed. That would be odd to me. But as I referenced earlier he (needed) to get to his destination and so he went, that is a prime example of The Road to Abilene thought process. Gets many pilots.
I have to go back over my notes to find some other anomalies. Such as he did contact the tower or not. No one responded when they should have when he did not land. I have some notes from a Civil Air Patrol guy I need to find.
Interesting perspective on JFK Jr. flight training. Thank you. I think your knowledge and common sense helped. I guess he (and Kobe) took a chance due to scheduling/ impatience and it cost them dearly.
Wonder why the other pilot cancelled on JFK Jr. ...