Guys like to collect things. It does not matter what it is there is likely someone collecting it, and especially if it has a sentimental attachment of some sort. Guitars are a good example they can be an attachment to the person's past which may have lead to a professional career. It also means that he will look for the best way to exhibit the guitars, a demonstration of how much he loves the guitars. In short he is going to do his best to create exhibition designs so that it is a memorial to the guitars, both for his past and so that the guitars may be used again.
The usual methods to exhibit guitars are either to hang them on wall through hooks that hold the guitar up and away from the wall, or using floor stands. The decision to go either way usually depends on the number of guitars, with floor stands used if there are only a few guitars and wall hooks if there a number of them. There is a compromise of the two exhibition designs, with a few guitars on the ground and most of them hanging this compromise is usually used when the collector wants to highlight a few of the guitars, and possibly even keep one ready for use.
The exact exhibition used depends on the type of guitar. It is not uncommon for an electric guitar display to feature an amp or two in case the collector decides to play, either to keep up practice or just to show off to his friends. There may be a general restriction against playing in the house, but the collector is probably going to ignore that restriction every so often it is his house, after all, and he decides when to break the rules. However, exhibition designs can allow for the proper theatre when he decides to play a guitar solo and wants to hear how he plays.
Even at a convention there is room for exhibition designs. Guitar stands can be used to highlight the guitars that the exhibitor wants to focus on. The guitars that potential clients can get their hands on are the most likely to sell after all, they are more emotional available than guitars hanging on a wall or behind the counter. There are some advantages to using guitar stands in your display they make the guitars look better and more personable, making them even more part of the collector's life, just like any good collector's item should be.