In reply to ralphio: I've had my partner take a fall off a traverse whilst leading half way up El Cap on a 10.3mm single. We hard a core shot 15m into the rope and the next pitch was my block to lead. so I know from experience what can happen to ropes.
Selecting an alpine route means doing your research and working out whether you need to abseil before you even start the approach.
For most standard non technical snow plods a 30m half rope or randonee rope will be fine.
If you have loads of rock, scrambling, pitched climbing, abseiling etc then you choose the appropriate rope, rack, and equipmemt for the task at hand.
Alpine climbing varies massively from walking along a glacier to climbing mixed vert terrain at altitude. Like comparing walking up easy path up ben nevis in winter and climbing grade X on the north face. Different things, different strategies, different gear required.