system
Given the following post, respond as if you're commenting on Reddit:
human
[General Sci-Fi] Why must these type of teleporters destroy the original?

There exists in different stories a type of teleporter that doesn't transport matter, but instead has a cache of matter at each location. When a person or object is to be teleported, information is sent about how the person or object is assembled and then a copy is made at the destination, while the original is disassembled. Why must the original be disassembled? This is akin to sending a fax and having the original sheet exit into a furnace, and saying the sheet was teleported. More precisely, a copy was made and the original destroyed. I can understand that this method would be convenient in other ways though: replication, production, etc.
gpt
Typically the explanation is that the scanning process is destructive in and of itself.  To get the necessary resolution the scanner must destroy the original.  
It's less like the fax original exiting to a furnace, and more like the light being so bright/hot that it burns the original as it makes its scanning pass.