Soloing was much more common when I first started, which re-inforced my concern that I maybe wasn't a real climber (It only took one long 15 minutes stuck on a slimy, rounded top-out in mid-summer to make me realize it wasn't for me). Many very good climbers could be seen at times soloing and I see no reason why it shouldn't be accepted without comment. It is just another type of climbing. I agree that I wouldn't want to stand around underneath.