Gary Stern gets my vote. I'm sure if all production ceased after B/W closed shop there would still be tens of thousands of old games around but less new people get exposed as those pins get old, destroyed and swallowed up in home collections.
By keeping the new pins rolling even weak pins, Stern kept interest alive and uptick with the release of Tron/AcDc
I think JJP could have taken over from scratch but it not have had fertile ground for $6500+ pins if not for AcDc/Tron etc..