http://www.basketball-reference.com/players/k/kingbe01.html
http://www.basketball-reference.com/players/w/worthja01.html
I've attached a link to both player's stats. In terms of games played, Worthy played a total of 923 regular season games. King played 874. Longevity is not an issue in this case. It's a case of having the luck to play in Showtime versus playing for some teams that barely made it in the post season.
At the same time, if you make Worthy the #1 option on a borderline playoff team I'm sure most of his "counting" stats would have improved.
King was an amazing player, though. How many small forwards, in any era, have had a season where they averaged 26 points per game on 57% shooting?
cough cough...Lebron James this year... 
Lebron, as great as he is, is "only" shooting 53%. Also, of course, if Lebron retired today he'd be in the HOF.
Adrian Dantley is about the only other guy I can think of who put up numbers like that as a small forward (or, I guess more accurately, a hybrid forward).
Just in King's era:
Kiki Vandeweghe did 26.7/55%, 29.4/56%
Walter Davis did 24.2/53%, 23.6/56%, 21.5/56%
Calvin Natt did 17.7/58%, 20.4/54%, 16.2/58%, 23.3/55%
Marques Johnson did 25.6/55%
James Worthy did 20.0/58%
Adrian Dantley did 28.0/58%, 30.7/56%, 30.3/57%, 30.7/58%, 30.6/56%, 29.8/56%
Julius Erving did 24.4/55%
Alex English did 25.4/55%
George Gervin did 27.2/54%, 29.6/54%, 33.1/53%
I mean King's numbers are definitely some of the best in the list I just dropped for combined ppg and fg%, but it's not that far out of the norm to consider it HOF worthy for a couple of good seasons I think.