Keep in mind, RV'ers are just a small subset of folks who buy an F150. The vast majority of F150's never haul more than a small utility trailer. My old S10 with a 4cyc could do that just fine.
I'm still not sold on the turboV6 for heavy hauling but for 99% of the people out there, they aren't hauling 10,000lb trailers on a regular basis and it should hold up fine. When it's empty, all that HP and torque makes for a fun ride but you can back off and get good fuel economy.
We'll have to see how they hold up for heavy hauling but that will have to be 5-8yrs in after they have seen some real abuse (not carefully planned manufacturers testing) and is such a small percentage of owners that if an issue does arise, its likely to be passed off as people abusing the truck. I do believe these engines are here to stay.
When they make it the standard engine for the F250/350, I will know Ford is ready to consider it an engine for heavy duty use.