Out of respect.
TimothyD, the problem with climbing below Severe is that there aren't all that many routes in many locations, so those that are are polished to buggery. With the locations that do have lots of easy routes then they're usually full of beginners/groups/schools and are very busy and polished to buggery too.
Plus climbing VDiffs is a bit boring.. it's a threshold thing. Above a certainly level I start to crap myself and panic; below that I am bored - I can climb a load better than I can handle mentally, if that makes sense.
I spent a long time trying to attack HVS and failing, which could be part of the problem.