I grew up in central NJ about a 40 min drive from EWR. I can probably count on one hand the number of times we flew out of JFK (or LGA for that matter). And we went on a lot of vacations.

If you live in Staten Island or Manhattan you may be relatively indifferent between the two (and that's a large population base), but otherwise you'll have a strong preference for one over the other based on convenience.