If he doesn't make anyone's list of top 5--even if you're 17 years old--there's really something wrong. More than anyone out there, he bridged the gap between the Scot Schmidt era and the New Canadian Airforce. He was stomping backflips off 40-50' cliffs years before Seth even went upside down. He pretty much paved the path for pro skiers and sponsorships in the mid-90s.
He is the reason anyone--Pollard, Seth, Tanner, you, anyone--skis on fat skis today, and he is the reason for the existence of rockered, reverse sidecut skis. He didn't make slight modifications to ski technology like other pros out there with their own pro models, he revolutionized what we ski on. In his segment in Fetish, on fat skis a year before anyone clued in, he opened every pro's eyes to how fast you could go with floatation. He organized an association (IFSA) to oversee big mountain comps.
He's starred in ski films longer than half the kids listed as "most influential" have been alive. He had his own movie, "There's Something About McConkey" that won all kinds of awards. He brought humor to skiing when there was little. He basically invented skiBASE jumping because he wanted to fly and ski lines no one else could. He was the first person to ever do a switch front flip. He won several skiercross races, mogul and big mountain events. He competed in Gravity Games big air throwing huge baranis and was the only skier out of several park specialists to hit a sketchy summer X-Games jump backwards in 1999 (switch back 360 and 540).
He was Seth before Seth really became the Seth we know today, and Seth used McConkey for inspiration and motivation.
We ski the way we do today because of McConkey as much as anyone out there, even if you don't really know it.