Penalty is a game of nerves and this change gives immense advantage to team going second. For ex- today morata would have been under more pressure after tibo's miss. And ox would have been more calm considering Chelsea missed two pens and he has less pressure.
Unnecessary change if you ask me. Why fix those things which need not require fixing.
Even if this system gave the second kicker an advantage, that still leaves it on par with the previous system which gave the first kicker an advantage.
The difference is, we have actual statistical evidence showing that the previous system aided the first kicker, whereas we have no evidence that this system is unfair in the same way.
I don't see why a 60/40 advantage to one team wouldn't require fixing, especially when attempting to fix it involves such a minor, painless change.