Agreed, my only issue is when theyre loose and flailing around, but i just snip them off.
My issue would more the be how do you carry them, they're long and pokey and could easily be bent, or poke holes in bags and other things.
As other have said if it was a drive side rear I'd need all the tools to strip off the cassette etc, it gets the point of where do you stop, do you carry spare headsets, BBs? pedals? tyres? If I was setting out on LEJOG with my current wheel which is starting to suffer a few spoke failures. It would probably be more expedient to get them all changed before setting off.
At the end of the day there are all sorts of calamities that could befall a rider and bike on any tour, help isnt usually far away.
The most awkward issue I have ever suffered was a puncture on the Camel Trail 20 miles from camp, I had a spare tube, but unfortunately it was the wrong size, the problem was it was 1AM so no other riders to ask for a scab, no LBS to pop into.