I would be curious to understand what is the reasoning behind that.

Not every dev agrees with this. John Carvalho argues that on-chain division of sats is equal to inflating the supply of bitcoin.

Modus

So this Policy is not fixed

 that’s good 

allark

bitcoin

Is a Satoshi infinitely divisible?

Also keep in mind that if in the future there is a good reason to increase granularity below sats that benefits the majority of the network and hurts no one, it is not unthinkable that it would be implemented.