morgan,
I suggest that, rather than trying to, "break the voodoo curse," you should embrace his newfound love of Harleys. Harleys are cool too, in their own way. It's a different trip than what we're into, but it's got two wheels and a motor, so it's OK in my book. Hell, if money were no object, there'd be a really cool, tricked-out Harley chopper in my garage next to my Ducs.
In the final analysis, this, "us vs. them," "sportbike vs. cruiser," mentality is divisive and counterproductive to motorcycling. I say, "invite them to the table," rather than excluding them. We like different kinds of bikes, but at the end of the day, we're all bikers. Just my opinion.
Elton