system
Given the following post, respond as if you're commenting on Reddit:
human
[Do Androids Dream of Electric Sheep?] Why make androids the way they are in the first place?

The Pitch Meeting answer is obviously, "*So the story can happen.*" But why?

There are only three differences between a human and an android. Empathic responses, whatever is in their spinal cord, and their short lifespan. Surely at some point along the production line someone must have recognized what a disaster that can potentially be.

Considering they're essentially meant to be thralls, it would have seemed far more prudent to manufacture them with barcode tattoos genetically engineered on their foreheads.

At the very least, they should have access ports that can be opened up so they can be shut down manually. (But if they had that, Deckard's job would be so much easier.)
gpt
Humans respond and relate better to humanoid-esque synthetics.  The more human, the more comfortable (most) people are at accepting them.  Once you've overcome the uncanny valley, then acceptance is far more likely.

That said, most of these type of technological creations and inventions are (at least initially) funded by government who have an intention or agenda, regardless if it is ever implemented or not.  In the case of replicants, they might have been intended to be spies or covert operatives of some sort.  Detection, identification, and ease of disabling them would be counter to that sort of purpose. 

Alas, once it's been accomplished, invented, and implemented (if even not for it's original intent) you can't really put the genie back in the bottle.