That's mostly due to Lucas Art's impact on the industry. Prior to Loom, all click and point adventure games had situations where you could either die or run into a point where you badly fail a puzzle to the point that you'll never be able to solve it on the current file you are playing. Once Loom was released, the LucasArts Game Design Philosophy came into play.
This has been used for every Lucas Arts adventure game (and a few others) since then, and considering that some Telltale employees formally worked for Lucas Arts in the past, it's no wonder why the death aversion exists. The only series of click and point adventure games that I know of that still goes against the philosophy are the King's Quest games.
Wikipedia snippet from Looms page Wrote:Loom was also the first game to follow the LucasArts Game Design Philosophy, which states that the player will never be killed or forced to restart the game and won't have to "spend hours typing in synonyms until [they] stumble on the computer's word for a certain object"
This has been used for every Lucas Arts adventure game (and a few others) since then, and considering that some Telltale employees formally worked for Lucas Arts in the past, it's no wonder why the death aversion exists. The only series of click and point adventure games that I know of that still goes against the philosophy are the King's Quest games.