To paraphrase Winston Churchill, stamp hinges are the worst form of mounts, except all others. Peelable hinges were a revolutionary innovation when they first became commercially available about 1920. Before that, hinging was done by using some old stamp selvage or gummed paper, and the results are hideous. Gummed paper never comes off of mint gummed stamps without damaging the stamps. It is because paper hinges of this type were so pervasive in early philately that so many earlier stamps have had the gum soaked off them (and consequently, it is paper hinges that are responsible for the large premium that truly "original gum" early stamps enjoy today).
When peelable hinges were invented they were a great innovation in the hobby. Stamps could be mounted inexpensively and then removed as many times as needed and remounted without any damage to the stamp itself and with only the most modest alteration of the pristine state of the gum. But in one of the most perverse examples of fashion winning out over function (and philatelists should never make fun of women in high heels), by 1970 what was on (or what wasn't on) the back of the stamp became more important than what was on the front. Stamp mounts were invented in the 1930s but had always been clunky affairs but became easier and easier to use as the decades progressed. The real push for Never Hinged collecting came from the stamp mount producers beginning in the 1960s. As stamp prices rose in the first great stamp speculation beginning in the 1960s, for the first time stamp prices were high enough so that it didn't seem silly to put your stamps in mounts that cost almost as much as the stamps themselves.
The situation now has taken on the proportion of the ornate tail feathers on a peacock