That's not really realistic. In practice some receivers do big sweeps and include unconfirmed inputs. Replacing the transaction means you need to pay the cost of the sweep, which you probably don't want to do (can be in the order of $100s of dollars).
> Beyond being paternalistic the issue I see with your proposal is thatits contrary to miner income
This applies to pretty much all non-standard transactions.
-------- Original Message --------
Subject: Re: [bitcoin-dev] BIP proposal: No chaining off replaceable transactions
Local Time: July 2, 2017 3:56 PM
UTC Time: July 2, 2017 8:56 PM
From: greg@xiph.org
To: Rhavar <rhavar@protonmail.com>
bitcoin-dev@lists.linuxfoundation.org <bitcoin-dev@lists.linuxfoundation.org>
On Sun, Jul 2, 2017 at 8:35 PM, Rhavar via bitcoin-dev
<bitcoin-dev@lists.linuxfoundation.org> wrote:
> ==Abstract==
>
> BIP125 allows transactions to opt into replaceability with a primary use
> case
> of allowing users to increase the fees of unconfirming transactions, helping
> create
> a more efficient fee market place.
I don"t really see how this is desirable: Just replace it-- the
receiver foolishly spent it at its own peril, spending a unconfirmed
payment from a third party is something that Core never does, it"s
reckless unless you"re doing something like CPFPing it to yourself,
which is harmless (either it"ll work, or it"ll fail and you"ll be fine
with that).
Beyond being paternalistic the issue I see with your proposal is that
its contrary to miner income-- you"re asking miners to ignore these
spends that otherwise they could accept. This seems unstable-- some
people would ignore your rule even if it were otherwise widely
adopted, leading to the network behavior having higher volatility.
Instead, perhaps a BIP that very strongly advises parties to not spend
unconfirmed outputs from third parties while making a payment to third
parties would achieve your end?