Deraileurs may be at their pinacle but personally I find them a pain for touring in terms of maintenance, vulnerability to the elements and whatever might get in their way. Roloff have a good reputation although they are costly and heavier and make taking out the wheel more complex. Can't have it all.
Definitely can't have it all; again, it's a matter of mitigating all of the compromises.
I don't know what you're thinking about with regards to maintenance and vulnerability with derailleurs. Yes, the drivetrain is all hanging out there like a nadsack waiting for a kick, but it's a pretty hardened sack. Anecdotally, my Deore LX derailleur has about 60,000 miles. I have replaced the pulleys a handful of times. I'm still using the original cage bolts, but they are about completely cammed-out now. I clean this thing maybe
once a year or so. I live in wet Portland OR, but used to live in salty, sandy, snowy Vermont. My front derailleur is a trashy C101 (it came stock) and it's just a science experiment in equipment abuse.
Bear in mind that an IGH does require maintenance, specifically oil changes. And in the case of some hubs, it is a proprietary oil. I think you're on the right track: the recent round-the-world record was set using a Rohloff/Gates drivetrain. The guy is an experienced tourer and he claimed that he would not have been able to pull off the record using a standard drivetrain. As it was, he still went through two (three?) belts. Then again, if I recall correctly he was sponsored by Gates and Rohloff, so take that as you will.
Both derailleur and internally geared hub have a shift cable that has to be kept in adjustment (only when it's new and is still stretching, or, as some would argue, only has that effect)
With Rohloff hubs, the indexing is internal to the hub, so cable bed-in is much less of an issue, if at all.