I agree with many points here. But ultimately for me the issue is the way glass changes how a print appears. Unless you have the lighting just perfect on a print framed behind glass, the glass ruins it. It takes away your strong blacks and adds a hint of green to the image, as well as adds glare from lights. I know there's AR glass, but for the money it's not reasonable. I enjoy viewing my finest prints with a matting and holding in my hands. Every bit of detail, tonality, and print color comes across amazingly. It's funny, many prints are framed on my walls. Once in a while I will take them out and view them with just the mat and think 'wow, why can't I enjoy this view all the time??' I have no track lighting in my home, and am considering adding some. All prints are simply viewed with weak ambient room light or sunlight from outside.
For shows, prints go behind glass which offers protection obviously, but lighting has to be right as well to bring out all the print has to offer.