Again, there's another comment by someone who never owned one, but goes off what someone else said. Perhaps the mechanic was abusive, or not much of a mechanic at all. I know mechanics that open the hood far too often and ruin a perfectly good vehicle that needed nothing to begin with.
Funny people brought up bulletproofing the 6.0, never thought this would get melted down this far. In reality, the majority of the problems come from clogged EGR coolers, and dirty EGR valves. Both which won't happen when maintained properly. The head gaskets just don't let go from normal operation. The EGR cooler (and oil cooler) get clogged up from not maintaining the coolant, thus the cooler doesn't cool the EGR gasses. These superheated gasses get reintroduced in to the cylinder and causes all kinds of problems. From blown head gaskets, to ruining injectors. Then add the high oil temps because that cooler is clogged, and the gummed up EGR valve and it's a big mess.
All of this can be prevented several ways. You can keep the coolant fresh, switch over to ELC coolant (CAT or red color usually), delete the EGR system altogether, install aftermarket coolers with big passages that won't clog, and also do head studs if you might want to add a tuner. This will lead to a happy 6.0 owner.
Yes that costs money, thousands in fact. Yes it usually involves pulling the cab (depends on who's doing the work). Each diesel truck has their weak points, you're going to put money in to a Dodge or Chevy, or Ford somewhere...pick your poison.
OP, here's a long read, but it has factual information in it:
http://www.littlepowershop.com/common-6-0-powerstroke-problems-issues-and-fixes/