people dont earn from sending transactions.. sending transactions is not mining
people pay fee's to send a tx
transactions are batched together into a block and a miner then secures the block and gets a reward plus the fees of the total transactions in the block

..
the original solo miner of the block that confirmed a tx from 2010 already got paid for confirming it.. its called the tx fee (0.99btc)
the original solo miner of that block in 2010 is no longer mining current transactions today, so doesnt deserve residual income

the residual income a solo miner from 2010 gets.. is from holding onto the TXfee(0.99btc)/blockreward(50btc) from 2010
earning 50btc blockreward+ fee's in 2010 (50.99btc  block 57043) for mining was worth $0.15297($0.003 x 50.99) in 2010.. but now worth $5.6m

so by the solo miner that mined the block containing the bitcoin pizza transaction can earn more by just holding the reward.
so no need for royalty.. (which would just end up with lots of dust outputs and bloating the chain per tx paying all tx senders of all previous spends of tx)

A result of your scheme would be blocks full of transactions with people sending bitcoins to themselves just to get that perpetual royalty.

I cannot think of a reason for implementing this, miners already earn coin-base rewards for confirming the block.

Where is this percentage supposed to come from, the bitcoin being sent or the remaining bitcoins yet to be mined? None of these will work for obvious reasons, it will also be terrible for privacy, imagine getting a percentage of a transaction which was used for illegal trades.

This sounds like some faux-complex approach shitcoins use to try and get people to buy their product.

- Jay -

So post about it in the altcoin area.
For the reasons already given it is a horrible idea for BTC.