I'm also an avid mountain biker. Been mountain biking since 1985. The last bike i built would have retailed for $7k. Modding a truck can cost a ton of money. I bet if people added up what all the mods have cost them, they would be pretty shocked. For me, I knew the only reason I would do expensive mods was if I was planning on really using it for what I was building it for. Those that put thousands into suspension, bumpers, winch, skids, snorkel, etc just so they can cruise the mall don't make sense to me. But, to each his own, I reckon. If they want to perform Sic Mods so they can negotiate the speed bumps at the mall, who am I to judge.
So, someone like Ash who wheels his rig sees the benefit of having a very functional and strong roof rack. When I was recently in Death Valley 4wheeling, one of the cool things I did with my Gobi style rack is stand up on top and get a better view point of the landscape. I was able to spot a trio of wild burros which was pretty cool.