The number of 1-2 night shows seems to be steadily increasing in the Tampa Bay area. The one-nighters last about 4-5 hours! I understand tying up donated space, as in Regions Bank, for example. However, many galleries are also doing this. Some multitasking spaces basically use art (and artists) as cheap wallpaper. A particular large space on 9th comes to mind.
With installations, some are very difficult to maintain, specially if they include animals and/or fish, Like Eva Avenue's memorable Gold Room, and installations also rarely result in sales -- and take up a lot of floor space.
The short lives of these shows also severely limit the possibility for artists to sell work, though the majority of work tends to sell on opening night. It serves the community to have accessibility to shows for more than a night or two, though it can be argued that very few people in this area go to galleries during the week.
When it comes to shows funded by grants, it seems absurd to invest money into a project that lasts one-third the flight of a Mayfly.