If you don't own a Jeep Wrangler Unlimited, Sport, Rubicon, etc. you may not get this. So, here's a little info I found on the internet I thought I would share.
Finally, some claim the wave began when civilians started buying Jeeps and taking them off road. The shared fun and excitement of tackling seemingly impossible trails and obstacles in the nimble Jeep, naturally builds a kinship with other Jeepers. The wave acknowledges that shared understanding and appreciation of the Jeep's amazing capabilities and the enjoyment ownership can bring.