This only applies to optical astronomers, of course! I think that they still do sneak a peak once in a while, usually to check on the rough focus of the telescope before inserting the photographic plate. But the fact of the matter is that most 'back ends' of telescopes are packed with sophisticated imagers, and the telescope pointing and focus are monitored by computers, so that there is no technical need for astronomers to actually look through telescopes anymore; at least not the big 'research grade' monsters. Time is valuable, and optical inspection is very inefficient. Many astronomers do enjoy looking through their own telescopes just like any other 'amateur astronomer' and many of us have small telescopes at home, in a closet.