a not uncommon alpine type belay is simply to rap the rope around a boulder/horn a few times …
also there are plenty of times on easy ground where you simply use a horn/edge as a pivot point (think pulley) for a quick (belay)
not to mention that its not uncommon to thread the rope around horns/features on a climb as "protection" especially on a ridge
this use of natural pro wears on the rope quite a bit, and has a significant risk of damaging/cutting a thinner rope
now plenty of highly experienced folks have climbed multipitch and alpine on single half ropes …. remember that for those folks rarely place any pro, and simply dont fall … much of the time they are just simulclimbing … ask yourself if you are at that level, or whether you will be using features as belays/protection
if the latter, a durable rope is not a bad idea
also remember that a rope can provide a false sense of security … if you rope up climbing without putting in any or insufficient protection, you can be less safe than soloing … as youll drag your partners down in a fall
this happens over and over again in the accident reports
heres one that happened locally this year
On Jan. 11, the three appear to have been walking up a steep gully, known as the central couloir, wearing crampons, according to RCMP.
They were roped together, near the top of the couloir, when they fell about 600 metres to their deaths, said police.
The central couloir of Joffre Peak is well-known among mountaineers and extremely steep, said a backcountry skier who has climbed it.
"It's a very serious route … steep enough that if you do start to fall, it is possible that you will not be able to self-arrest," said Paul Cordy of Squamish, B.C.
Cordy said it's a route that should only be attempted by experienced climbers who know how to build anchors in the snow to stop a fall.
But even if they did everything right, he said, safety isn't guaranteed on such steep terrain.
"It could just happen, in the event of a fall, if the anchors aren't as secure [in the snow] as you want them to be."
http://www.cbc.ca/news/canada/british-columbia/stephanie-grothe-elena-cernicka-neil-mackenzie-identified-as-joffre-peak-climbing-victims-1.2899722